Question

Write the formula by criss-cross method of Magnesium chloride.

Answer 1

The symbol of magnesium is ‘Mg’, having a valency of 2⁺.

The symbol of choride is ‘Cl’ with valency 1^-.

We will find the formula of magnesium chloride by criss-cross method in 3 easy steps.

Step 1 –

Write the formula of magnesium chloride:

Symbol Valency

Magnesium Mg 2⁺

Chloride Cl 1^-

Step 2 –

Write each symbol with its valency:

Mg²⁺ Cl^1-

Step 3 –

Interchanging the valencies:

$$\begin{gathered} \mathrm{Mg}\mathrm{Cl} \\ \searrow \swarrow \\ {2}^{+}{1}^{-} \end{gathered}$$

The formula of the compound Magnesium chloride is MgCl₂.