3 What is the mass of 15.0 x1015 atoms of uranium?

Mass = 595 * 10⁻⁸ g

Explanation:

Given dа ta:

Number of atoms of uranium = 15.0 * 10¹⁵ atoms

Mass of uranium = ?

Solution:

The given problem will solve by using Avogadro number.

It is the number of atoms, ions and molecules in one gram atom of element, one gram molecules of compound and one gram ions of a substance.

The number 6.022 * 10²³ is called Avogadro number.

For example,

1 mole of uranium = 6.022 * 10²³ atoms of uranium

1 mole * 15.0 * 10¹⁵ atoms / 6.022 * 10²³ atoms of uranium

2.5 * 10⁻⁸ moles

Mass of uranium:

Mass = number of moles * molar mass

Mass = 2.5 * 10⁻⁸ moles * 238 g/mol

Mass = 595 * 10⁻⁸ g