Question

How many atoms are in a sample of chromium with a mass of 31 grams? O a 2.4 x 1024 atoms of chromium b 3.6 x 1023 atoms of chromium 1.9 x 1026 atoms of chromium Od 1.5 x 1023 atoms of Chromium​

Answer 1

Answer:

b. 3.66x10²³ atoms of chromium.

Explanation:

First we calculate how many moles are there in 31 grams of chromium, using its molar mass:

• Molar Mass of Chromium = 51 g/mol (This can be found on any periodic table)

• 31 g ÷ 51 g/mol =  0.608 mol

Then we calculate how many atoms are there in 0.608 moles, using Avogadro's number:

• 0.608 mol * 6.023x10²³ atoms/mol = 3.66x10²³ atoms

The correct answer is thus option b. 3.66x10²³ atoms of chromium.