Question

(a) 4.12 x 10^15 atoms U

Answer 1

Answer:

1.63ₓ10⁻⁶ g of U

139.03 g of H

0.385 g of O

141.8 g of Pb

Explanation:

In first place, we need to convert the number of atoms to moles, as we know that 1 mol of anything occupies 6.02×10²³ particles

Therefore:

4.12×10¹⁵ atoms of U . 1 mol / 6.02×10²³ atoms = 6.84×10⁻⁹ moles of U

8.37×10²⁵ atoms of H . 1 mol /6.02×10²³ atoms = 139.03 moles of H

1.45×10²² atoms of O . 1 mol /6.02×10²³ atoms = 0.0241 moles of O

4.12×10²³ atoms of Pb . 1 mol /6.02×10²³ atoms = 0.684 moles of Pb

Moles . Molar mass = Mass (g)

6.84×10⁻⁹ moles of U . 238.03 g/mol = 1.63ₓ10⁻⁶ g of U

139.03 moles of H . 1 g/mol = 139.03 g of H

0.0241 moles of O . 16 g/mol = 0.385 g of O

0.684 moles of Pb . 207.2 g/mol = 141.8 g of Pb