Question

How many potassium atoms are in 250.0 grams of potassium?

1.66 x 10^−24 atoms K

3.85 x 10^24 atoms K

1.51 x 10^26 atoms K

5.88 x 10^27 atoms K

Answer 1

Hi!

The correct option would be 3.85x10^(24)

To find the number of atoms in 250g of potassium, we need to first calculate the number of atoms in

1 mole of Potassium = 39g which contains 6.022x10^(23) atoms of K

(Avogadro's constant value for the amount of molecules/atoms in one mole of any substance)

Solution

So as 39g of Potassium contains 6.022x10^(23) K atoms

1g of Potassium would contain 6.022x10^(23) / 39 = 1.544 x10^(22) atoms

So 250g of Potassium would contain 1.544x10^(22) x 250 = 3.86x10^(24) atoms