Question

How many atoms are there in 10 g of Kr?

Answer 1

With the correct number of significant figures you get 7 x 10^22

Answer 2

From the periodic table, we know that 1 mole of Krypton has a molar mass of 83.798 grams/mole.

So 10 grams would have (10/83.798) which is 0.1193345903 moles.

If we multiply this by Avogadro's number, we get the amount of Krypton atoms in 10 grams.

0.1193345903 x 6.02 x 10^23 = 7.184 x 10^22 atoms

Accounting for significant figures, the answer would be: 7 x 10^22 atoms