Group 17 of the Periodic Table
Group 17 of the periodic table (Halogens) has 6 elements: Fluorine, Chlorine, Bromine, Iodine, Astatine and Tennessine. Elements in a group have a similar last electron shell, so they show similar chemical properties. Moving down a group, the number of shells and the atomic radius usually increase.
Halogens
The halogens are the group 17 elements: highly reactive nonmetals that form salt compounds with metals.
Element list
| Atomic no. | Symbol | Name | Atomic mass | Phase | Short configuration |
|---|---|---|---|---|---|
| 9 | F | Fluorine | 18.998 | Gas | [He] 2s² 2p⁵ |
| 17 | Cl | Chlorine | 35.45 | Gas | [Ne] 3s² 3p⁵ |
| 35 | Br | Bromine | 79.904 | Liquid | [Ar] 3d¹⁰ 4s² 4p⁵ |
| 53 | I | Iodine | 126.9 | Solid | [Kr] 4d¹⁰ 5s² 5p⁵ |
| 85 | At | Astatine | 210 | Solid | [Xe] 4f¹⁴ 5d¹⁰ 6s² 6p⁵ |
| 117 | Ts | Tennessine | 294 | Solid (a theoretical prediction) | [Rn] 5f¹⁴ 6d¹⁰ 7s² 7p⁵ |
Frequently asked questions
What are the group 17 elements of the periodic table?
The group 17 elements are Fluorine (F), Chlorine (Cl), Bromine (Br), Iodine (I), Astatine (At) and Tennessine (Ts).
How many elements are in group 17?
Group 17 of the periodic table has 6 elements (excluding the lanthanides and actinides).