Group Trends
Like other groups, the candidates of this family show patterns in its electron configuration, especially the outermost shells resulting in trends in chemical behavior:
| Z | Element | No. of electrons/shell |
|---|---|---|
| 9 | fluorine | 2, 7 |
| 17 | chlorine | 2, 8, 7 |
| 35 | bromine | 2, 8, 18, 7 |
| 53 | iodine | 2, 8, 18, 18, 7 |
| 85 | astatine | 2, 8, 18, 32, 18, 7 |
The halogens show a series of trends when moving down the group—for instance, decreasing electronegativity and reactivity, and increasing melting and boiling point.
| Halogen | Standard Atomic Weight (u) | Melting Point (K) | Boiling Point (K) | Electronegativity (Pauling) |
| Fluorine | 18.998 | 53.53 | 85.03 | 3.98 |
| Chlorine | 35.453 | 171.60 | 239.11 | 3.16 |
| Bromine | 79.904 | 265.80 | 332.00 | 2.96 |
| Iodine | 126.904 | 386.85 | 457.40 | 2.66 |
| Astatine | (210) | 575.00 | 610 (?) | 2.20 |
Read more about this topic: Halogen
Famous quotes containing the words group and/or trends:
“With a group of bankers I always had the feeling that success was measured by the extent one gave nothing away.”
—Francis Aungier, Pakenham, 7th Earl Longford (b. 1905)
“Thanks to recent trends in the theory of knowledge, history is now better aware of its own worth and unassailability than it formerly was. It is precisely in its inexact character, in the fact that it can never be normative and does not have to be, that its security lies.”
—Johan Huizinga (1872–1945)