Binary ionic compound : It is a type of compound that is made up of the ions of the two different elements in which one element is a metal and another element is a non-metal.
From the given options, option (A) is a binary ionic compound because in this compound Mg is a metal which combine with the a non-metal element chlorine.
While the other options are the covalent compounds that is formed by the combination of non-metal and non-metal elements.
Explanation: A chemical reaction is said to be in a state of equilibrium when the rate of the forward reaction equals the rate of the backward reaction, thus, there is no net change in the concentration of reactants and products.
