The left-hand block only

The middle block only

Everything below and to the left of the red line

Everything above and to the right of the red line

One electron

2 electrons

8 electrons

10 electrons

Boron

Sulfur

Neon

Chlorine

Lithium

Nitrogen

Sodium

Oxygen

Argon

Neon

Sodium

Magnesium

To get a full first shell

To empty their inner shells

To get a full outer shell

To become more reactive

Because they already have full outer shells

Because they have an even number of electrons

Because they only need to gain one electron

7, 8, 2

2, 8, 7

17

2, 8, 8

Gain 1 electron

Gain 2 electrons

Lose 1 electron

Lose 2 electrons

An aluminium atom lost three electrons

A nitrogen atom lost three electrons

A nitrogen atom gained three electrons

A neon atom gained electrons

+

-

2+

2-

It will gain 2 electrons and become a 2- ion.

It will gain 3 electrons and become a 3- ion.

It will lose 5 electrons and become a 5- ion.

It will gain 3 electrons and become a 3+ ion.

lost two outer electrons

gained two outer electrons

lost one outer electron

gained 6 electrons

Gain one electron

Lose one electron

Gain two electrons

Lose two electrons

Na⁺

Na^-

Na²⁺

Na₊