Group 7 element
Encyclopedia : G : GR : GRO : Group 7 element
| Group | 7 |
|---|---|
| Period | |
| 4 | 25 Mn |
| 5 | 43 Tc |
| 6 | 75 Re |
| 7 | 107 Bh |
All of these elements are classed in Group 7 because their valence shell holds four electrons. Technetium has no stable isotopes. Technetium, and promethium, are the only two such elements before polonium, after which no known element has a stable isotope.
| >Explanation of right side periodic table slice: | Transition metals
| atomic number in red are gases
| atomic number in black are solids | solid borders are older than the Earth (Primordial elements) | dotted borders are made artificially (Synthetic elements) | dashed borders have no isotopes older than the earth |
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