3.47 x 
atoms of gold have mass of 113.44 grams.
Explanation:
Data given:
number of atoms of gold = 3.47 x
mass of the gold in given number of atoms = ?
atomic mass of gold =196.96 grams/mole
Avagadro's number = 6.022 X
from the relation,
1 mole of element contains 6.022 x atoms.
so no of moles of gold given = 
0.57 moles of gold.
from the relation:
number of moles = 
rearranging the equation,
mass = number of moles x atomic mass
mass = 0.57 x 196.96
mass = 113.44 grams
thus, 3.47 x atoms of gold have mass of 113.44 grams
D is the answer I believe.
The mass stays constant as a substance changes from a liquid to a gas.
The Law of Conservation of Mass states that, in ordinary chemical reactions, mass is neither destroyed nor created.
That is, the mass of the reactants must equal the mass of the products.
2H₂O(ℓ) ⟶ 2H₂O(g)
1 g 1 g
If the mass of liquid water is 1 g, the mass of the water vapour must be 1 g.
Even though the water vapour is a gas and you can’t see it, it still has a mass
of 1 g.
