ionic bonding

how are ions formed by electron loss or gain?

Atoms take part in chemical reactions to achieve a full outer shell of electrons, which is very stable. They can achieve this by losing, gaining or sharing electrons from the outer shell. If an atom loses or gains electrons, the number of protons and electrons are no longer equal and a charged ion is formed.

what ions do metals (group 1,2,3) form?

positive ions = cations

→ because groups 1,2 and 3 need to lose their outer electrons to react, and electrons are negatively charged so therefore they form a positive ion as they have more protons than electrons

what ions do non-metals (group 6,7) form?

negative ions = anions

→ because groups 6 and 7 need to gain electrons to react, and electrons are negatively charged so therefore they form a negative ion as they have more electrons than protons

what charge do elements in group 1 have?

(element symbol)⁺

what charge do elements in group 2 have?

(element symbol)²⁺

what charge do elements in group 3 have?

(element symbol)³⁺

what charge do elements in group 5 have?

(element symbol)^3-

what charge do elements in group 6 have?

(element symbol)^2-

what charge do elements in group 7 have?

(element symbol)^-

charge of silver

Ag⁺

charge of copper

Cu²⁺

charge of iron (II)

Fe²⁺

charge of iron (III)

Fe³⁺

charge of lead

Pb²⁺

charge of zinc

Zn²⁺

what is the charge of hydrogen?

H⁺

what is the charge of hydroxide?

OH^-

what is the charge of ammonium?

NH^₄+

what is the charge of carbonate?

CO₃^2-

what is the charge of nitrate?

NO₃^-

what is the charge of sulphate?

SO₄^2-

how can you write formulas for compounds formed between ions?

drop and swap - swap numbers on the symbols