Science Concepts Encyclopedia
Explore key science concepts like density, acid-base reactions, and crystal growth. Each concept page explains the science, shows a visual diagram, and connects to hands-on experiments you can try.
Acids & Bases
How acids and bases interact, from the color-changing indicators that reveal pH to the fizzing neutralization reactions you can see and measure in everyday experiments.
Acid Erosion
Acid erosion is what happens when an acid slowly eats away at a solid material, like vinegar dissolving an eggshell.
Acid Rain
Acid Rain is rain mixed with harmful gases from the air that can damage plants and soil.
Acid-Base Reactions
Acid-Base Reactions is what happens when an acid and a base mix and create new things like bubbles or color changes.
Anthocyanins
Anthocyanins is the natural color in red cabbage that changes from pink to green depending on whether a liquid is acidic or basic.
Ascorbic Acid
Ascorbic acid is the chemical name for vitamin C, a nutrient found in fruits and vegetables that breaks down when heated.
Calcite
Calcite is a mineral found in many rocks that fizzes when it touches vinegar.
Calcium Carbonate Reactions
Calcium Carbonate Reactions is what happens when an acid like vinegar meets a calcium carbonate surface like an eggshell, dissolving it and producing bubbles.
Carbon Dioxide Gas Production
Carbon Dioxide Gas Production is what happens when two substances mix and release carbon dioxide gas, like the fizzing you see when baking soda meets vinegar.
Chemical Indicators
Chemical Indicators are substances that change color to show whether a chemical reaction has happened or how acidic a liquid is.
Iodine Test
Iodine Test is a way to check if food contains starch by watching for a dark color change.
Malic Acid
Malic acid is a natural sour compound found in apples and other fruits.
Neutralization
Neutralization is what happens when an acid and a base cancel each other out, creating something milder.
pH
pH is a scale from 0 to 14 that measures how sour or bitter a liquid is.
pH and Aquatic Life
pH and Aquatic Life is the study of how acid levels in water affect animals living there.
pH Indicators
pH Indicators is a group of substances that change color to show whether a liquid is an acid or a base.
Soil pH
Soil pH is how sour or mild the dirt is, which changes how well plants can grow.
Titration
Titration is a way to measure how much acid or base is in a liquid by adding drops until the color changes.
Vitamin C
Vitamin C is a nutrient in fruits and vegetables that breaks down when exposed to heat or air.
Fluids, Density & Gases
Why some things float and others sink, how gases push and compress, and what happens when liquids refuse to mix. These concepts connect through the shared physics of pressure, mass, and volume.
Air Pressure
Air pressure is the push of air on everything around it, and it changes with the weather.
Atmospheric Pressure
Atmospheric Pressure is the weight of air pushing down on everything around you.
Buoyancy
Buoyancy is the upward push water gives to anything placed in it.
Carbonation
Carbonation is the process of dissolving carbon dioxide gas into a liquid to create bubbles.
Combustion
Combustion is a chemical reaction where a substance burns by combining with oxygen, releasing heat and light.
Density
Density is how much stuff is packed into a space, which is why some things float and others sink.
Gas Laws
Gas Laws are rules that tell how heat, push, and space change the way gases act.
Gas Pressure
Gas Pressure is the push that trapped gas makes against the walls of its container, like the force that launches a film canister rocket.
Immiscible Liquids
Immiscible Liquids is what happens when two liquids, like oil and water, refuse to mix and instead form separate layers.
Osmosis and Dehydration
Osmosis and dehydration is how water moves through a thin barrier, pulling moisture out of things like an orange soaked in alcohol.
Specific Gravity
Specific gravity is a number that tells you how heavy a liquid is compared to plain water.
Electricity & Electrochemistry
From batteries to electrolysis, these concepts explore how chemical reactions produce electricity and how electricity drives chemical change. Metal reactivity ties them all together.
Displacement Reactions
Displacement Reactions is when a stronger metal pushes a weaker metal out of a solution, trading places with it.
Electrochemical Cells
Electrochemical Cells is how two different metals in a liquid create electricity, like a homemade battery built from zinc and copper.
Electrolysis
Electrolysis is using electricity to break water apart into hydrogen gas and oxygen gas.
Hydrogen Gas
Hydrogen gas is the lightest gas in the world, and you can make it by running electricity through water.
Metal Reactivity Series
Metal Reactivity Series is a ranking of metals by how eagerly each one reacts, showing why a zinc-and-copper battery produces more voltage than other metal pairs.
Semiconductor Materials
Semiconductor Materials are solids that conduct electricity only part of the time, like silicon in solar cells.
Temperature and Electrical Resistance
Temperature and Electrical Resistance is how heat changes how well power flows through a material.
Voltage and Current
Voltage and Current are the push and flow of electricity — voltage pushes, and current is how much flows.
Voltage and Electric Current
Voltage and electric current is the push and flow of tiny charges through a wire.
Heat & Energy
How temperature drives reactions faster, makes matter change state, and moves heat through fluids. These concepts share a common thread: energy in motion.
Arrhenius Equation
Arrhenius Equation is a math formula that shows how heat makes things happen faster.
Boiling Point
Boiling Point is the temperature at which a liquid turns into gas and forms bubbles.
Calorimetry
Calorimetry is measuring how much heat energy is stored inside something, like a nut, by burning it.
Candle Burn Rate
Candle Burn Rate is how fast a candle uses up its wax as it burns.
Chemical Energy
Chemical Energy is energy stored inside a substance that comes out when it burns or reacts.
Conduction
Conduction is how heat moves through a solid object from the hot end to the cold end.
Convection
Convection is the way heat moves through a liquid or gas by making warmer parts rise and cooler parts sink.
Curie Point
Curie Point is the heat level where a magnet stops working and loses its pull.
Energy Conversion
Energy Conversion is when one kind of energy changes into a different kind of energy.
Entropy
Entropy is a measure of how spread out and mixed up energy becomes over time.
Exothermic Reactions
Exothermic Reactions is when a chemical change gives off heat, like the warm foam that bursts from an elephant toothpaste experiment.
Heat Absorption
Heat Absorption is how a surface soaks up warmth from the sun or other hot sources.
Heat Retention
Heat Retention is how well something holds onto warmth instead of letting it escape.
Heat Transfer
Heat transfer is the movement of heat from something warm to something cooler, like an oven warming food inside it.
Newtons Third Law
Newton's Third Law is the rule that every push or pull creates an equal push or pull back.
Phase Changes
Phase Changes is what happens when matter shifts between solid, liquid, and gas, like ice melting into water.
Radiation
Radiation is energy that moves through space as waves, like heat from the sun.
Radiation Effects on Living Organisms
Radiation Effects on Living Organisms is how energy like microwaves or X-rays can help or harm living things.
States of Matter
States of Matter is how stuff around you can be solid like ice, liquid like water, or gas like steam.
Steam and Water Vapor
Steam and Water Vapor is water that has turned into a gas from being heated.
Sublimation
Sublimation is when a solid turns directly into a gas without melting into a liquid first.
Surface Area
Surface Area is the total amount of outside space on an object that touches its surroundings.
Temperature Effects on Reaction Rate
Temperature Effects on Reaction Rate is how heating or cooling a substance changes how fast it reacts, like sugar dissolving faster in hot water than cold.
Temperature Measurement
Temperature Measurement is how we use tools like thermometers to find out how hot or cold something is.
Thermal Conductivity
Thermal Conductivity is how quickly heat moves through a material, like metal warming fast in your hand.
Thermal Energy
Thermal Energy is the heat stored inside an object because of how fast its tiny parts are moving.
Thermal Expansion
Thermal Expansion is when things get bigger because they are heated up.
Thermal Insulation
Thermal Insulation is using a material to slow down how fast heat moves in or out.
Crystals & Solutions
What happens when you dissolve, concentrate, and crystallize. From growing crystals to understanding why salt melts ice, these concepts explore the boundary between dissolved and solid.
Colligative Properties
Colligative Properties are ways that adding a substance to a liquid changes how it freezes, boils, or behaves, based on how many particles you add.
Crystal Growth
Crystal growth is what happens when tiny particles in a liquid slowly stack together into a solid shape.
Crystallization
Crystallization is what happens when dissolved sugar or other substances slowly form solid shapes as water dries up.
Dissolution and Solubility
Dissolution and solubility is how well something breaks apart and mixes into a liquid until it disappears.
Evaporation
Evaporation is when a liquid turns into a gas and moves into the air, even without boiling.
Freezing Point Depression
Freezing Point Depression is what happens when adding something like salt or sugar to water makes it freeze at a colder temperature.
Nucleation
Nucleation is when tiny bits of dust or smoke give water drops or crystals a surface to form on.
Osmosis
Osmosis is the movement of water through a barrier from where there is more water to where there is less.
Supersaturation
Supersaturation is when water holds more dissolved material than it normally can, so crystals form as it cools.
Light & Color
How light interacts with matter — from glow-in-the-dark phosphorescence to the UV absorption that sunscreen blocks. Chromatography reveals hidden colors; Beer's Law measures concentration through light.
Angle of Incidence
Angle of Incidence is the tilt between a light ray and the flat surface it hits.
Beer's Law
Beer's Law is the rule that light gets weaker as it passes through more of a colored liquid, like sunscreen blocking UV rays.
Chemiluminescence
Chemiluminescence is light produced by a chemical reaction instead of heat, like the glow inside a glow stick.
Chlorophyll
Chlorophyll is the green pigment in leaves that captures sunlight to make food for plants.
Chromatography
Chromatography is a way to separate the hidden colors inside a mixture by letting a liquid carry them apart on paper.
Focal Point
Focal Point is the spot where a curved mirror or lens sends all its light together.
Light Absorption and Reflection
Light Absorption and Reflection is how surfaces soak up or bounce back light and heat.
Parabolic Reflectors
Parabolic Reflectors are curved mirrors shaped to aim all sunlight at a single spot.
Phosphorescence
Phosphorescence is the glow some materials give off in the dark after soaking up light.
Photodegradation
Photodegradation is how light from the sun breaks down colors and things.
Refractometry
Refractometry is a way to measure how much sugar or other stuff is dissolved in a liquid by shining light through it.
Ultraviolet Radiation
Ultraviolet radiation is light from the sun that you cannot see but can cause sunburns.
UV Absorption
UV Absorption is what happens when a material soaks up ultraviolet light instead of letting it pass through.
Surface & Interface
The science at the boundary: surface tension holds water drops together, surfactants break that tension, and capillary action pulls liquids through narrow spaces.
Absorption
Absorption is when a material soaks up a liquid or gas and holds it inside.
Adsorption
Adsorption is when atoms or molecules stick to the outer surface of a solid instead of soaking in.
Capillary Action
Capillary action is the way water travels upward through narrow spaces on its own, like when a paper towel soaks up a spill.
Detergent and Surfactant Effects
Detergent and Surfactant Effects is how soap and cleaning agents change water and harm or help living things like plants.
Oil Spill Cleanup
Oil spill cleanup is the work of removing oil from water and shores after a spill.
Surface Tension
Surface Tension is the thin, stretchy skin that forms on top of water because water pulls itself together.
Surfactants
Surfactants are molecules in soap that grab onto both water and oil, letting you wash greasy things clean.
Materials & Reactions
How materials transform through chemical reactions — rust eats iron, soap forms from fat, eggs cook irreversibly, and catalysts speed it all up without being consumed.
Activated Carbon
Activated carbon is a form of charcoal with tiny holes that trap dirt and toxins from water or air.
Atomic Structure
Atomic structure is the arrangement of tiny particles inside an atom, which you can model by grouping dried beans into a center cluster and an outer ring.
Catalysis
Catalysis is when a substance speeds up a chemical reaction without being used up itself, like yeast making hydrogen peroxide foam instantly.
Coagulation
Coagulation is when heat or acid makes a liquid protein turn firm and solid, like an egg cooking in a pan.
Control Variables
Control variables are the things in an experiment you keep the same so your test is fair.
Corrosion
Corrosion is the slow chemical breakdown of metal when it reacts with water, air, or other substances around it.
Oxidation
Oxidation is a chemical reaction where a substance combines with oxygen, like when lemon juice on paper turns brown from heat.
Oxidation and Antioxidants
Oxidation and antioxidants is how air breaks things down and how some vitamins slow that damage.
Pesticides
Pesticides are chemicals used to kill bugs, weeds, or other pests that harm crops.
Protein Denaturation
Protein Denaturation is what happens when heat or acid makes proteins in milk unfold and clump together into solid chunks.
Saponification
Saponification is the chemical reaction that turns fat or oil into soap when mixed with a strong base.
Tensile Strength
Tensile Strength is how much pulling force a material can handle before it breaks apart.
Toxicology
Toxicology is the study of how poisons and harmful chemicals affect living things.
Environment & Ecosystems
Where chemistry meets the living world — how pollution affects plant growth, contaminants move through water and soil, and ecosystems respond to chemical stress. These concepts connect laboratory science to real-world environmental impact.
Algae Growth
Algae Growth is how tiny green plants in water get bigger and spread when they have warmth and light.
Aquifer Contamination
Aquifer Contamination is when bad stuff gets into water stored deep under the ground.
Chlorine Toxicity
Chlorine toxicity is the harm that too much chlorine does to living things like plants and seeds.
Environmental Pollution
Environmental pollution is when harmful things get into the air, water, or soil and cause damage.
Smoke and Fire Ecology
Smoke and Fire Ecology is the study of how wildfires and smoke help plants grow and forests stay healthy.
Soil Pathogens
Soil pathogens are tiny living things in dirt that make plants sick and stop them from growing well.
Water Pollution
Water pollution is when harmful things get into rivers, lakes, or oceans and make the water unsafe.
Food & Biochemistry
The chemistry hiding in your kitchen — how enzymes break down food, bacteria multiply on meat, proteins change when cooked, and nutrients transform through digestion, ripening, and processing. These concepts connect biology and chemistry through the foods you eat every day.
Bacteria Growth
Bacteria Growth is the rapid spread of tiny germs on food when it sits at warm temperatures too long.
Cut Flower Preservation
Cut Flower Preservation is keeping picked flowers fresh longer by feeding them sugar water.
Digestion
Digestion is how your body breaks food into tiny pieces small enough to use for energy.
Enzymatic Reactions
Enzymatic Reactions is when special proteins in food or your body speed up changes, like breaking down vitamin C in orange juice.
Food Irradiation
Food irradiation is a way to kill germs in meat and other foods using energy beams.
Lactose
Lactose is a natural sugar found in milk that gives it a slightly sweet taste.
Macronutrients
Macronutrients are the proteins, fats, and carbs in food that give your body energy to grow and move.
Maillard Reaction
Maillard Reaction is what turns food brown and gives it new flavors when you cook it with high heat.
Moisture Content
Moisture content is how much water is trapped inside a food or material.
Rehydration
Rehydration is what happens when dried food soaks up water and returns to its soft, full size.
Saturated and Unsaturated Fats
Saturated and unsaturated fats are two types of fat that differ in how their carbon atoms bond together.
Starch
Starch is a type of sugar that plants make to store energy in foods like rice and potatoes.
Starch Gelatinization
Starch gelatinization is what happens when dry starch grains soak up water and heat, swelling into a soft gel.
Weather & Atmosphere
How air, water, and energy interact in the atmosphere to create weather — from cloud formation and fog to tornadoes, wind patterns, and the instruments that measure them all.
Anemometer
Anemometer is a tool that measures how fast the wind blows by counting how quickly its cups spin.
Barometer
Barometer is a tool that measures the push of air around us to help predict the weather.
Cloud Formation
Cloud Formation is what happens when warm, moist air cools and tiny water drops appear in the sky.
Condensation
Condensation is what happens when warm, moist air cools down and turns into tiny water drops.
El Nino
El Nino is a warm ocean current that changes weather all over the world.
Fog
Fog is a cloud that forms close to the ground when warm, moist air cools down fast.
Friction
Friction is the force that slows things down when they rub against each other.
Greenhouse Effect
Greenhouse Effect is how trapped air in a closed space warms up faster than open air around it.
Humidity
Humidity is the amount of water held in the air around you.
Ocean Temperature
Ocean temperature is how warm or cold seawater is, which changes how much salt the water can hold.
Ocean-Atmosphere Interaction
Ocean-Atmosphere Interaction is the way warm ocean water and the air above it trade heat and moisture, shaping weather worldwide.
Precipitation
Precipitation is water that falls from clouds to the ground as rain, snow, sleet, or hail.
Salinity
Salinity is how much salt is mixed into water, like the ocean or a glass of warm water.
Temperature
Temperature is a measure of how hot or cold something is.
Tornado
Tornado is a spinning column of air that reaches from a storm cloud down to the ground.
Vortex
Vortex is a spinning flow of water or air that forms a funnel shape, like the swirl inside a flipped bottle.
Weather Forecasting
Weather Forecasting is using simple tools like a homemade barometer to predict what the sky will do next.
Wind Speed
Wind speed is how fast air moves from one place to another.
Earth & Geology
Rocks, minerals, and the forces that shape the Earth — from earthquakes and volcanoes to the slow weathering that turns mountains into sand.
Earthquakes
Earthquakes are sudden shaking of the ground caused by rocks slipping along a crack in the earth.
Elastic Rebound
Elastic Rebound is when rocks bend from stress, then snap back and cause an earthquake.
Groundwater
Groundwater is water that soaks into the ground and fills the tiny gaps between rocks and soil.
Ice Wedging
Ice wedging is when water seeps into cracks in rock, freezes, and expands until the rock splits apart.
Landslides
Landslides are large masses of rock, soil, or debris that slide down a slope.
Magnetic Field
Magnetic Field is the invisible force around a magnet that pulls on metals and makes compass needles move.
Magnetometer
Magnetometer is a tool that measures how strong or which way a magnetic field points.
Mineral Identification
Mineral Identification is figuring out what type of rock or mineral you have by testing how it looks, feels, and reacts.
Mohs Hardness Scale
Mohs Hardness Scale is a ranking of ten minerals from softest to hardest based on which ones can scratch the others.
Permeability
Permeability is how easily water or other liquids can pass through a material like soil or rock.
Plate Tectonics
Plate Tectonics is the slow movement of large pieces of Earth's surface.
Rock Porosity
Rock porosity is the amount of tiny open spaces inside a rock that can hold water.
Sea-Floor Spreading
Sea-floor spreading is the slow movement of ocean floor away from cracks where hot rock rises up.
Seismic Waves
Seismic Waves is the shaking that moves through the ground when rocks slip or break.
Soil Horizons
Soil horizons are the distinct layers of soil you can see when you dig straight down into the ground.
Soil Porosity
Soil porosity is the measure of empty spaces between soil particles where water and air can hide.
Stratigraphy
Stratigraphy is the study of rock layers and what they reveal about Earth's history.
Streak Test
Streak test is scratching a mineral across a rough plate to see the color it leaves behind.
Subduction
Subduction is when a big piece of the ground slowly slides under another piece and goes deep down.
Tephra
Tephra is the rock, ash, and debris that a volcano throws into the air during an eruption.
Volcanic Eruptions
Volcanic eruptions are events where hot melted rock, gases, and ash burst out from inside Earth.
Weathering
Weathering is the slow breaking down of rocks by water, wind, ice, and living things.
Waves & Tsunamis
How energy travels through water — from the physics of wave speed and propagation to the devastating power of tsunamis and the shallow-water effects that amplify them near coastlines.
Shallow Water Effect
Shallow Water Effect is how waves slow down and grow taller as they move into shallow water near shore.
Tsunamis
Tsunamis is a set of huge ocean waves that form when the sea floor shifts fast.
Wave Propagation
Wave Propagation is how a wave moves energy from one place to another without carrying matter along.
Space & Astronomy
The science beyond Earth's atmosphere — from the phases of the Moon and the tilt that causes seasons to the structure of galaxies and the physics of black holes. These concepts explore how we observe, model, and understand objects in space.
Atmospheric Refraction
Atmospheric Refraction is the bending of light as it passes through layers of air at different temperatures.
Black Holes
Black Holes is what forms when a huge star dies and its pull grows so strong that not even light gets out.
Comets
Comets are balls of ice, dust, and rock that grow bright tails when they travel close to the Sun.
Earth's Axial Tilt
Earth's Axial Tilt is the lean of our planet that makes sunlight hit some places more directly than others.
Earth's Rotation
Earth's rotation is the steady spin of our planet that moves the sun across the sky each day.
Electromagnetic Spectrum
Electromagnetic Spectrum is the full range of light and energy, from radio waves to gamma rays, mostly invisible to our eyes.
Galaxy Structure
Galaxy structure is the shape and pattern that billions of stars form when gravity pulls them together.
Hawking Radiation
Hawking radiation is the slow release of energy that causes black holes to shrink and fade away over time.
Lunar Phases
Lunar Phases is the changing shape of the lit part of the Moon as it circles Earth each month.
Micrometeorites
Micrometeorites is tiny bits of space rock that fall to Earth every day and collect in dust on rooftops and leaves.
Parallax
Parallax is the shift in where an object appears when you view it from two different spots.
Pinhole Camera
Pinhole Camera is a simple box with a tiny hole that lets light in to make an image on the back wall.
Planetary Differentiation
Planetary Differentiation is how a planet sorts itself so heavy stuff sinks to the center and light stuff rises to the top.
Scale Models
Scale Models is a way to shrink huge things, like the solar system, so they fit in a small space.
Seasons
Seasons is the way Earth's tilt makes sunlight stronger or weaker at different times of year.
Solar Projection
Solar projection is a way to view the sun by letting light pass through a small hole onto a screen.
Solar System Scale
Solar System Scale is how we shrink the sun and planets to sizes and distances we can see and compare.
Solar Wind
Solar Wind is a stream of tiny bits shot out from the Sun that can shake Earth's magnetic field.
Stellar Classification
Stellar Classification is how we sort stars by their color and heat.
Sundial
Sundial is a tool that tells time by tracking where a shadow falls as the sun moves across the sky.
Sunspots
Sunspots are dark patches on the Sun that look darker because they are cooler than the area around them.
Solar Energy & Photovoltaics
How sunlight becomes usable energy — from photovoltaic cells that convert light into electricity to concentrated solar systems that focus the sun's heat.
Concentrated Solar Power
Concentrated Solar Power is when mirrors focus sunlight into one spot to make strong heat.
Dye-Sensitized Solar Cells
Dye-Sensitized Solar Cells are solar panels that use colored dye to catch sunlight and make power.
Photovoltaic Effect
Photovoltaic Effect is when light hits a solar cell and creates power.
Solar Cell Efficiency
Solar Cell Efficiency is how much of the sunlight hitting a solar cell gets turned into electricity.
Solar Energy
Solar Energy is light and heat from the sun that we can capture and use.
Animal Behavior & Ecology
Concepts related to animal behavior, adaptation, ecology, and interactions between organisms and their environments.
Animal Behavior
Animal Behavior is how animals act and respond to the world around them.
Animal Intelligence
Animal Intelligence is how well animals can learn new things and solve problems.
Animal Locomotion
Animal Locomotion is how animals move from one place to another.
Animal Memory
Animal Memory is how animals store and recall things they have learned before.
Animal Navigation
Animal Navigation is how animals find their way across long distances to reach a goal.
Beak Adaptation
Beak Adaptation is how a bird's beak shape matches the type of food it eats.
Biodiversity
Biodiversity is the variety of all living things found in a place.
Biological Clock
Biological Clock is the inner system that tells an animal when to sleep, wake, and eat.
Blood Glucose
Blood glucose is the sugar in your blood that gives every cell in your body the energy to work.
Brine Shrimp Biology
Brine shrimp biology is the study of how tiny salt-water shrimp hatch, grow, and react to their world.
Camouflage
Camouflage is the way an animal uses colors or patterns to blend in and hide from other animals.
Cellular Respiration
Cellular respiration is the way living cells break down food and turn it into energy they can use.
Chemoreception
Chemoreception is the way animals use smell and taste to sense chemicals around them.
Circadian Rhythm
Circadian rhythm is the body clock that tells an animal when to sleep, wake up, and eat.
Color Vision in Animals
Color vision in animals is how different species see and tell apart colors with cells in their eyes.
Conditioned Taste Aversion
Conditioned taste aversion is when an animal learns to avoid a food that once made it feel sick.
Convergent Evolution
Convergent evolution is when unrelated animals grow similar body parts from living in the same kind of place.
Daphnia as Model Organism
Daphnia as Model Organism is using tiny, see-through water fleas to test how substances affect a living body.
Ectothermy
Ectothermy is when an animal relies on the heat around it to warm or cool its body.
Evolutionary Divergence
Evolutionary Divergence is when one animal group slowly splits into two types that look and act very different.
Free Radicals and Aging
Free Radicals and Aging is the idea that harmful bits inside cells slowly damage the body over time.
Habitat Preference
Habitat Preference is when an animal picks one type of place to live over another.
Habituation
Habituation is when an animal stops reacting to something because it has seen or heard it many times.
Hearing Range
Hearing Range is the span of sounds, from low to high, that an animal can detect.
Heart Rate
Heart Rate is the number of times your heart beats in one minute.
Insect Ecology
Insect Ecology is the study of how bugs live, eat, and relate to the world around them.
Insect Repellent
Insect Repellent is a substance that keeps bugs away with a smell or taste they avoid.
Laterality
Laterality is the tendency to prefer one side of your body over the other, like being right-handed.
Maze Learning
Maze Learning is how animals get better at finding their way through a maze with practice.
Metamorphosis
Metamorphosis is when an animal completely changes its body shape as it grows up.
Natural Selection
Natural Selection is when living things with traits that fit their surroundings survive and have more young.
Pesticide Resistance
Pesticide Resistance is when bugs survive a spray that used to kill them.
Pharmacology
Pharmacology is the study of how drugs and chemicals change the way a body works.
Phototropism and Phototaxis
Phototropism and Phototaxis is how plants and animals move toward or away from light.
Predator-Prey Relationship
Predator-Prey Relationship is the link between animals that hunt and the animals they hunt for food.
Protoplasmic Streaming
Protoplasmic Streaming is the flow of fluid inside living cells that moves food and waste around.
Rodent Behavior
Rodent Behavior is how mice, rats, and squirrels act when they search for food, explore, and react to their surroundings.
Steroid Effects on Growth
Steroid Effects on Growth is how certain strong drugs can change the way living things grow and gain weight.
Stimulus and Response
Stimulus and Response is how a living thing senses a change around it and then reacts to that change.
Symbiosis
Symbiosis is when two living things help each other by living close together.
Taxonomy
Taxonomy is the system scientists use to sort and name all living things based on how they are related.
Territorial Behavior
Territorial Behavior is how animals claim and guard a space to keep other animals away from their food or shelter.
Thermoregulation
Thermoregulation is how living things control their body heat to stay at the right temperature.
Ultraviolet Radiation Effects
Ultraviolet Radiation Effects is how invisible light from the sun can change the growth, color, and health of living things.
Plant Biology & Growth
Concepts related to plant growth, development, reproduction, and responses to environmental factors.
Allelopathy
Allelopathy is when a plant releases chemicals that stop other plants from growing nearby.
Asexual Reproduction in Plants
Asexual Reproduction in Plants is how a plant grows a new plant from a piece of itself, like a cut stem.
Caffeine Effects on Plants
Caffeine Effects on Plants is the study of how caffeine changes the way plants grow.
Companion Planting
Companion planting is growing certain plants next to each other so they help each other grow better.
Drought Resistance
Drought resistance is a plant's ability to stay alive and healthy when water is scarce.
Earthworms and Soil Health
Earthworms and Soil Health is the study of how worms help plants grow by mixing and loosening dirt.
Electrical Stimulation in Plants
Electrical Stimulation in Plants is using small amounts of electric current to help plants grow faster.
Erosion
Erosion is when wind, water, or ice wears away rock and soil and moves it to a new place.
Fertilizers and Plant Nutrition
Fertilizers and Plant Nutrition is the study of how added nutrients in soil help plants grow taller and stronger.
Fruit Ripening
Fruit Ripening is the natural change that makes a fruit softer, sweeter, and ready to eat.
Germination
Germination is when a seed takes in water, swells, and sprouts into a new plant.
Gravitropism
Gravitropism is how plants sense gravity and grow their roots down and stems up.
Growing Media
Growing media is the material plants root into, such as soil, sand, water, or cotton.
Hydroponics
Hydroponics is a way to grow plants in water with added food instead of soil.
Nitrogen Cycle
Nitrogen Cycle is the way nitrogen moves through air, soil, plants, and back again.
Organic vs. Inorganic Fertilizer
Organic vs. Inorganic Fertilizer is a test of how plant food from nature or from a factory helps grass grow.
Photosynthesis
Photosynthesis is how plants use light, water, and air to make their own food and grow.
Plant Competition
Plant Competition is what happens when too many plants grow close and must share light, water, and food.
Plant Conditioning and Behavior
Plant Conditioning and Behavior is the study of how plants react to touch, light, or signals over time.
Plant Growth
Plant growth is how plants get bigger by making new cells using water, light, and nutrients from the soil.
Plant Hormones
Plant hormones are signals inside a plant that tell stems, roots, and leaves when to grow.
Planting Depth
Planting depth is how far down in the soil you place a seed before it grows.
Pollination and UV Patterns
Pollination and UV patterns is how hidden marks on flowers guide bees to carry pollen.
Salt Tolerance in Plants
Salt Tolerance in Plants is how well a plant can grow when there is salt in its water.
Seed Size and Vigor
Seed Size and Vigor is how a seed's size affects how fast and strong it grows.
Sound and Plant Growth
Sound and Plant Growth is the idea that music or noise can change how fast a plant grows.
Stomata
Stomata are tiny holes on leaves that open and close to let air in and water out.
Transpiration
Transpiration is how plants release water through tiny holes in their leaves into the air.
Tropisms
Tropisms is how plants grow toward or away from things like light, water, or gravity.
Vegetative Propagation
Vegetative Propagation is growing a new plant from a cut piece of a parent plant, not from a seed.
Vitamins and Plant Growth
Vitamins and Plant Growth is how added vitamins like vitamin D can change how fast or tall plants grow.
Water Quality and Plant Growth
Water Quality and Plant Growth is how the stuff mixed into water changes the way plants grow.
Wind and Mechanical Stress in Plants
Wind and Mechanical Stress in Plants is how wind pushes and bends plants, changing how they grow.
Human Body & Health
Concepts related to human anatomy, physiology, health, nutrition, and the functioning of body systems.
Anthropometry
Anthropometry is the study of body sizes and shapes, like how tall you are or how long your feet are.
Antibodies
Antibodies are tiny proteins your body makes to find and stick to germs so they can be destroyed.
Blind Spot
Blind Spot is a small area in each eye where you cannot see anything because no light sensors exist there.
Blood Pressure
Blood Pressure is the force your blood pushes against the walls of your blood vessels as your heart pumps.
Cell Size
Cell Size is how big or small the tiny building blocks are that make up every living thing.
Circulatory System
Circulatory System is your body's network of heart, blood, and blood vessels that moves food and air to every cell.
Exercise Physiology
Exercise Physiology is the study of how your body changes and responds when you move and stay active.
Hair Structure
Hair Structure is the layered design of each hair strand that gives it strength, color, and shape.
Immune System
Immune System is your body's built-in defense team that finds and fights germs to keep you healthy.
Iris and Pupil
Iris and Pupil is the pair of eye parts that control how much light enters your eye.
Kidney Function
Kidney Function is how your kidneys clean your blood and remove waste through urine.
Lung Capacity
Lung Capacity is the total amount of air your lungs can hold in one deep breath.
Microscopy
Microscopy is using a tool with lenses to see things too small for your eyes alone.
Olfaction
Olfaction is your sense of smell, which also shapes how you taste food.
Optic Nerve
Optic Nerve is the cord in your head that sends what your eyes see to your brain.
Pulse
Pulse is the beat you feel in your wrist or neck each time your heart pumps blood.
Pupillary Response
Pupillary response is how your pupils grow bigger in dim light and shrink in bright light.
Reaction Time
Reaction Time is how fast you respond to something you see, hear, or feel, like catching a ruler someone drops.
Reflexes
Reflexes is how your body moves on its own to keep you safe, like pulling your hand off a hot stove.
Respiratory System
Respiratory system is the group of organs that bring air into your body and push it back out.
Retina
Retina is the thin layer at the back of your eye that senses light and sends signals to your brain.
Sensory Systems
Sensory systems are the parts of your body that let you see, hear, smell, taste, and touch.
Skeletal Muscle Adaptation
Skeletal Muscle Adaptation is how muscles change their size and strength when you use them in new ways.
Systole and Diastole
Systole and Diastole is the two-part pumping rhythm of your heart: squeezing blood out, then filling back up.
Taste Perception
Taste Perception is how your brain reads flavors using signals from your tongue and your nose working together.
Urine Composition
Urine Composition is the mix of water, salts, and waste that your kidneys filter from your blood.
Mind, Memory & Learning
Concepts related to psychology, cognition, memory, learning, perception, and behavioral science.
Auditory Lateralization
Auditory Lateralization is how each ear sends sound to a different side of the brain for processing.
Auditory Learning
Auditory learning is when you learn best by hearing words spoken out loud.
Chunking
Chunking is grouping small pieces of information together so your brain can remember more at once.
Cognitive Development
Cognitive development is how your brain gets better at thinking, learning, and solving problems as you grow up.
Color Perception
Color Perception is how your brain reads the colors your eyes see and uses them to make sense of the world.
Color Psychology
Color Psychology is the study of how colors change the way people think, feel, and act.
Controlled Experiment
Controlled Experiment is a test where you change one thing and keep everything else the same to see what happens.
Emotion Recognition
Emotion Recognition is the ability to tell how someone feels by reading their face, voice, or body.
Endangered Species
Endangered Species is the study of animals and plants at risk of dying out forever.
Exercise and Cognition
Exercise and Cognition is the study of how physical activity affects thinking and brain power.
Expectation Bias
Expectation Bias is when what you believe will happen changes what you actually see, feel, or do.
Facial Expression
Facial Expression is a movement of the face muscles that shows what a person is feeling or thinking.
Gender Differences in Cognition
Gender Differences in Cognition is the study of how males and females may think in different ways.
Hand-Eye Coordination
Hand-Eye Coordination is your brain guiding your hands based on what your eyes see.
Long-Term Memory
Long-term memory is your brain's way of holding onto things you learned days, weeks, or even years ago.
Memory Recall
Memory Recall is the ability to bring back facts or events stored in your brain.
Mnemonic Devices
Mnemonic Devices is the use of tricks like rhymes or phrases to help you remember facts.
Motivation and Persistence
Motivation and Persistence is what drives you to start a task and keep going when it gets hard.
Multisensory Flavor Perception
Multisensory Flavor Perception is how your brain blends taste, smell, and sight to create flavor.
Multitasking
Multitasking is trying to do two or more things at once, which usually makes each one harder.
Narrative Memory
Narrative memory is how your brain recalls things better when you link them to a story.
Nature vs Nurture
Nature vs Nurture is the question of whether your traits come from birth or from life experience.
Observational Research Methods
Observational Research Methods is a way of studying people or animals by watching what they do without changing anything.
Olfactory Perception
Olfactory Perception is how your brain reads smells from your nose and uses them to shape how food tastes.
Operant Conditioning
Operant Conditioning is when an animal learns to repeat actions that lead to a reward.
Placebo Effect
Placebo Effect is when people feel or perform better simply because they believe a treatment or action will help them.
Reading Comprehension
Reading Comprehension is how well you grasp and recall what you read.
Second Language Acquisition
Second Language Acquisition is how people learn to speak and understand a new language.
Selective Attention
Selective Attention is your brain's ability to focus on one thing while ignoring everything else around you.
Self-Esteem
Self-Esteem is how good or bad you feel about yourself and what you can do.
Short-Term Memory
Short-term memory is your brain's ability to hold a small amount of information for a short time.
Sleep and Learning
Sleep and Learning is how rest at night helps your brain save and recall what you studied.
Sleep and Music
Sleep and Music is the study of how listening to music changes how fast and how well you fall asleep.
Spatial Reasoning
Spatial Reasoning is thinking about shapes, sizes, and how objects fit together in space.
Stereoscopic Vision
Stereoscopic Vision is your brain combining the slightly different views from each eye to see depth.
Stress and Cognitive Performance
Stress and Cognitive Performance is the study of how feeling nervous or pressured changes how well your brain thinks and remembers.
Stroop Effect
Stroop Effect is when reading a color word slows you down from naming the ink color it is printed in.
Study Habits
Study Habits is how you practice and review what you need to learn.
Subliminal Perception
Subliminal Perception is when your brain picks up on things you see or hear too fast to notice.
Survey and Questionnaire Design
Survey and Questionnaire Design is the skill of writing clear questions that get honest answers from people.
Survey Methodology
Survey Methodology is the study of how to ask questions so you get useful answers.
Time Perception
Time Perception is how your brain judges whether time moves fast or slow, even when the clock stays the same.
Visual Learning
Visual Learning is taking in new ideas by looking at pictures, charts, or colors.
Visual Perception
Visual Perception is how your brain makes sense of what your eyes see, sometimes adding or changing details on its own.