[tex]4Na_{(s)}+O_{2(g)}\rightarrow2Na_2O_{(s)}[/tex]
Answer: A
[tex]Na(23\times4=92g);O2(16\times2=32g);Na2O(23+23+16)\times2=124[/tex]
Explanation: Based on the Law of conservation of mass the total mass of the reactants will equal to the total mass of the products. This happens as matter is not destroyed.
