Answer:

1. NaCl

Na = 1 × 22.99 g/mol = 22.99 g/mol

Cl = 1 × 35.45 g/mol = 35.45 g/mol

Molar Mass of NaCl = 58.44 g/mol

% Na =  22.99/58.44 × 100% = 39.34%

% Cl = 35.45/58.44 × 100% = 60.66%

2. NH3

N = 1 × 14.01 g/mol = 14.01 g/mol

H = 3 × 1.01 g/mol = 3.03 g/mol

Molar Mass of NH3 = 17.04 g/mol

% N = 14.01/17.04 × 100% = 82.22%

% H = 3.03/17.04 × 100% = 17.78%