Atomic mass of Na: 23 g => 1 mol of Na = 23 g
Analysis of each choice:
A) 1. 4 mol = 1.4mol*23g/mol = 32.2 g
B) 1 mol of atoms = 6.02 x 10^23 atoms => 1.02 x 10^24 atoms / 6.02 x 10^23 atoms/mol = 1.69 mol
1.69mol*23g/mol = 38.87 g
C) 23 g
D) 6.02 x 10 ^23 atoms = 1 mol = 23 g.
Then the option B) is the right answer.
