2.7.2a: recall the characteristic physical properties of the elements limited to the appearance of solutions of the elements in water and hydrocarbon solvents

Fluorine = yellow gas

Chlorine = pale green gas

• yellow/green in hexane
• chlorine water is pale yellow

Bromine = red-brown liquid

• orange-brown in hexane

Iodine = grey solid

• purple in hexane

Astatine = black solid

Properties:

• all form acidic hydrides
• electronegativity decreases as you go down the group
• they all exist as diatomic molecules