So density = mass/volume

per internet search, density of gold = 19.3 grams/cu.cm

That is 19.3 gm per 1 cm^3.

One sheet of gold leaf is 0.0000127 cm thick.

If this one sheet weighs 19.3 grams, what would be its area?

(area in cm^2)*(0.0000127 cm) = 1 cm^3

area = 1 /0.0000127 = 78,740 cm^2

How many sq.m is that?

(78,740 cm^2)(1 m^2 /(100cm)^2 = 7.874 m^2

So, that means per 19.3 gm of gold, 7.874 m^2 of gold leaf can be made.

There are 28.35 gm of gold to be made into gold leaf, so,

(28.35 gm)(7.874m^2 /19.3 gm) = 11.566 m^2

Therefore, 11.566 square meters of gold leaf can be obtained from 28.35 grams of gold. ---------answer.