a.

Hydrochloric acid

b.

Calcium hydroxide

c.

Kerosine

d.

Water

a.

Dissolution of salt in water

b.

Rusting of iron

c.

Melting of ice

d.

Separating a mixture by distillation

a.

s-orbitals

b.

p-orbitals

c.

d-orbitals

d.

f-orbitals

a.

are both metals

b.

belong to the same group

c.

belong to the same period

d.

are positioned diagonally to each other