Mg gained mass because it went from being a single element (on the reactant side) to being a molecule (on the product side).
Atomic mass Sodium ( Na ) = 22.98 u.m.a
22.98 g ----------------- 6.02x10²³ atoms
175 g ------------------- ?? atoms
175 x ( 6.02x10²³) / 22.98 =
4.58x10²⁴ atoms of Na
hope this helps!
It’s DEFINITELY 2 like DEFINITELY
