States of Matter
States of Matter is how stuff around you can be solid like ice, liquid like water, or gas like steam.
Think of it this way
Water in your kitchen shows all three states of matter. Ice cubes in a tray hold a fixed shape — that is the solid state. Pour water into a glass and it takes the shape of the glass — that is the liquid state. Heat that water and steam rises into the air, spreading out to fill the whole kitchen — that is the gas state.
Explaining states of matter by grade level
Water can be hard ice, a flowing liquid, or steam you can see. When you freeze a flower in ice, the water turns solid. Heat the ice and it melts back to liquid. Matter changes form but does not go away.