Halogen

5 elements

Highly reactive nonmetals in Group 17 of the periodic table. They have seven valence electrons and readily form -1 anions. Halogens exist in all three states of matter at room temperature and are strong oxidizing agents.

9 Gas F Fluorine 18.998 u

MP: -219.7 °C BP: -188.1 °C

17 Gas Cl Chlorine 35.45 u

MP: -101.5 °C BP: -34.0 °C

35 Liquid Br Bromine 79.904 u

MP: -7.3 °C BP: 58.9 °C

53 Solid I Iodine 126.9 u

MP: — BP: —

85 Solid At Astatine 210.0 u

MP: — BP: —

Comparison Table

#	Symbol	Name	Mass (u)	Melting Pt	Boiling Pt	Density	Phase
9	F	Fluorine	18.998	-219.7 °C	-188.1 °C	0.001696	Gas
17	Cl	Chlorine	35.45	-101.5 °C	-34.0 °C	0.003214	Gas
35	Br	Bromine	79.904	-7.3 °C	58.9 °C	3.1028	Liquid
53	I	Iodine	126.9	—	—	—	Solid
85	At	Astatine	210.0	—	—	—	Solid