Question

1. ionic compounds
2. write the formula

(hint: must criss cross)
a) beryllium iodide
b) aluminum oxide
c) barium fluoride

1. write the name

a) k₂s
b) nai
c) li₂o

Explanation:

1. Write the formula

a) Beryllium iodide

• Step1: Determine the ions

Beryllium (\(Be\)) has a charge of \(+ 2\) (\(Be^{2+}\)), iodide (\(I\)) has a charge of \(-1\) (\(I^{-}\)).

• Step2: Criss - cross the charges

Using the criss - cross method, the formula is \(BeI_{2}\).

b) Aluminum oxide

• Step1: Determine the ions

Aluminum (\(Al\)) has a charge of \(+3\) (\(Al^{3+}\)), oxide (\(O\)) has a charge of \(-2\) (\(O^{2 -}\)).

• Step2: Criss - cross the charges

Criss - crossing the charges gives \(Al_{2}O_{3}\).

c) Barium fluoride

• Step1: Determine the ions

Barium (\(Ba\)) has a charge of \(+2\) (\(Ba^{2+}\)), fluoride (\(F\)) has a charge of \(-1\) (\(F^{-}\)).

• Step2: Criss - cross the charges

Using the criss - cross method, the formula is \(BaF_{2}\).

2. Write the name

a) \(K_{2}S\)

• Step1: Identify the ions

\(K^{+}\) is potassium ion and \(S^{2 -}\) is sulfide ion.

• Step2: Name the compound

The name is potassium sulfide.

b) \(NaI\)

• Step1: Identify the ions

\(Na^{+}\) is sodium ion and \(I^{-}\) is iodide ion.

• Step2: Name the compound

The name is sodium iodide.

c) \(Li_{2}O\)

• Step1: Identify the ions

\(Li^{+}\) is lithium ion and \(O^{2 -}\) is oxide ion.

• Step2: Name the compound

The name is lithium oxide.

Answer:

1.
a) \(BeI_{2}\)
b) \(Al_{2}O_{3}\)
c) \(BaF_{2}\)
2.
a) potassium sulfide
b) sodium iodide
c) lithium oxide