a.

Ca

b.

Na

c.

Zn

d.

Al

a.

1g of hydrogen molecules

b.

16g of oxygen molecules

c.

32g of oxygen molecules

d.

35.5 of chlorine molecules

a.

The mass of a unit volume of the gas compared to equal volume of water vapour

b.

The mass of a unit volume of the gas compared to equal volume of hydrogen

c.

The mass of a unit volume of the gas compared to equal volume of oxygen

d.

The mass of a unit volume of the gas minus the vapour pressure of water

a.

They are good conductors of electricity

b.

They ionize by electron loss

c.

Their oxides are acidic

d.

They have high melting points