Science Fair Project Encyclopedia
Group 7 element
A Group 7 element is an element in periodic table group 7 (IUPAC style) in the periodic table, which consists of:
- manganese (25)
- technetium (43)
- rhenium (75)
- bohrium (107)
All of these elements are classed in Group 7 because their valence shell holds four electrons. Technetium has no stable isotopes. Technetium, and promethium (61), are the only two such elements before polonium, after which no known element has a stable isotope.
| Key to color coding in table slice on right: | Transition metals |
Color coding for these atomic numbers: At room temperature, all are solid; red indicates item is synthetic and does not occur naturally.
10-26-2009 08:16:03
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The contents of this article is licensed from www.wikipedia.org under the GNU Free Documentation License. Click here to see the transparent copy and copyright details