Question

4 what is the formula for the compound between sodium (na) and oxygen (o)? a nao b na₂o₂ c nao₂ d na₂o

Explanation:

Step1: Determine the valency of sodium and oxygen

Sodium (Na) has a valency of +1. Oxygen (O) has a valency of -2.

Step2: Use the criss - cross method

To form a neutral compound, the charges must balance. Using the criss - cross method, we get \(Na_2O\) (since \(2\times(+1)+(-2)=0\)). \(Na_2O_2\) is sodium peroxide where oxygen has a different oxidation state (-1) which is not the case for the simple oxide formed by the normal valency of oxygen (-2). \(NaO\) and \(NaO_2\) do not have balanced charges.

Answer:

D. \(Na_2O\)