Chemical Bonding

Question 1

How do atoms attain full valence shells

Answer 1

Non-metals gain electrons to attain a full valence shell and form negative ions (anions)
Metals lose electrons to attain a full valence shell and form positive ions (cations)

Question 2

Ionic bonding

Answer 2

Take place between oppositely charged ions
Compounds made from metal and non-metal

Ionic bonds are formed by electron transfer, where atoms donates electrons to non-metal atoms
Ions are arranged in an ionic lattice and are held together by electrostatic forces of attraction

E.g. sodium (metal) + chlorine (non-metal) –> sodium chloride (NaCl)

Question 3

Covalent bonding

Answer 3

Formed between non-metal atoms
Bond is formed by sharing of electrons between atoms

1 covalent bond = 2 electrons shared by 2 atoms (each one contribute 1 electron)

Covalent substances can be simple or large molecules

e.g. methane

Covalent bonds are also formed between atoms of same element. E.g. Hydrogen H2