Question

Which of the following would contain the same
number of atoms as 20g of calcium?
a)24g of magnesium b) 12 g of carbon
c)24g of carbon d) 12 g of magnesium

Answer 1

Answer:

12 gram of magnesium

Explanation:

1 mole of calcium contains 40 grams of calcium.

Therefore 0.5 mole of calcium contains 20 grams of calcium.

Now one mole of magnesium contains 24 grams of magnesium. Therefore 0.5 mole of magnesium contains 12 grams of magnesium.

This implies that 0.5 mole of calcium will have 3.022 * 10^23 atoms.

and 0.5 mole of magnesium will also have 3.022 * 10^23 atoms.