Represent each of the following awns using Lewis notation:

(a) beryllium

(b) calcium

(c) lithium

Draw simple diagrams to show how electron are arranged in the following covalent molecules:

a) Calcium oxide (CaO)

(b) Water (H₂O)

(c) Chlorine (Cl₂)

Represent the molecule H₂O using Lewis notation.

Represent each of the following molecules using Lewis notation:

(a) bromine gas (Br₂)

(b) Calcium chloride (CaCl₂)

(c) carbon dioxide (CO₂)

(d) Which of the three molecules listed above contains a double bond?

Two chemical reactions are described below.

• Nitrogen and hydrogen react to firm ammonia (NII)

• Carbon and hydrogen bond to form a molecule of methane (NH₃).

For each reaction, give:

(a) The valency of each of the atoms involved in the reaction.

(b) The Lewis structure of the product that is formed.