Density allows you to find that for the coin to look like gold, the correct answer is: the mass must INCREASE
Density is the relationship between the mass of a body and its volume is constant for solids and liquids.
ρ = m / V
where ρ is the density, m the mass and V the volume of the body
The mass of the coin is
m = ρ V
initially the coin is silver (Ag) with density, ρ_{Ag} = 10.94 g/cm³ and the density of gold (Au) is ρ_{Au} = 19.32 gr/cm³
As the density of gold is greater than the density of silver, we must use some chemical method, for example electroplating, to introduce a small layer of gold or other golden material on the surface, as this layer is very thin, the increase in volume is very small, the mass of the coins is
m₁ = ρ_{Ag] V
m₂ = ρ_{Au} V
where m₁ and m₂ are the masses of the silver and gold coins, respectively
What
ρ_{Au} > ρ_{Ag}
the mass of the coin must increase
With the density we can find that for the peel to look like gold the mass must INCREASE
learn more about density here: brainly.com/question/15164682