group 7

What are the elements of group 7 and what are they known as

Fluorine, chlorine, bromine, iodine and astatine - known as the halogens

Are group 7 metals or non-metals

Non- metals

Are halogens poisonous

Yes

The halogens are ____ molecules

Diatomic

What does diatomic mean

They form molecules made of pairs of atoms sharing electrons (covalent)

What charge are halide ions

-1

Fluorine state + appearance at room temp

Yellow gas

Chlorine state + appearance at room temp

Pale yellow - green gas

Bromine state + appearance at room temp

Red - brown liquid

Iodine state + appearance at room temp

Grey solid

Halogens colour in solutions

Fluorine - colourless

Chlorine - pale green

Bromine - orange

Iodine - dark brown

The melting and boiling points of the halogens ____ going down the group bc….

Increase

Increasing intermolecular forces (diatomic = covalent) as the atoms become larger so more energy required to overcome forces

Reactivity of group 7 _____ as you go down the group bc…

Decreases

Outer shell further form positive nucleus, makes it harder to gain extra electron

What happens in a halogen displacement reaction

A more reactive halogen displaces a less reactive halogen from an aqueous solution of its halide

What happens when halogens react with some metals

Form ionic compounds which are metal halide salts

Describe the formation of sodium chloride

1. Sodium atoms donates electron to chlorine atom

2. They now both have a full outer shell and are charged, sodium +1 chloride -1

3. There is SEFABOCI forming sodium chloride

Halogens react with non metals to form..

Simple molecular covalent structures