Answer:
% Mg = 16.2 % ≈ 16 %
%N = 18.9 % ≈ 19 %
% O = 64.9 % ≈ 65 %
Step-by-step explanation:
Step 1: Data given
Molar mass Mg(NO3)2 = 148 g/mol
Molar mass Mg = 24 g/mol
Molar mass N = 14 g/mol
Molar mass O = 16 g/mol
Step 2: Calculate the percent composition
% Mg = (24/148) *100%
% Mg = 16.2 % ≈ 16 %
% N = (2*14 / 148) * 100%
%N = 18.9 % ≈ 19 %
% O = (6*16/148) * 100%
% O = 64.9 % ≈ 65 %