70.906 g
We are given;
We are required to calculate the mass of Chlorine
But since Chlorine gas is a molecule;
But, molar mass of Chlorine gas = 70.906 g/mol
Then;
70.906 g Of chlorine gas = 2 × 6.022 × 10^23 atoms
= 1.20 × 10^24 atoms
Thus;
For 1.2 × 10^24 atoms ;
= ( 70.906 g/mol × 1.2 × 10^24 atoms ) ÷ (1.20 × 10^24 atoms)
Therefore, 1.20 × 10^24 atoms of chlorine contains a mass of 70.906 g
=