4.81*10^24 atoms of lithium

Mass = 55.52 g

Explanation:

Given dа ta:

Number of atoms of Li = 4.81*10²⁴ atom

Number of grams = ?

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,

1.008 g of hydrogen = 1 mole = 6.022 * 10²³ atoms of hydrogen

For Li:

4.81*10²⁴ atom * 1 mol / 6.022 * 10²³ atom

8 moles

Mass in gram:

Mass = number of moles * molar mass

Mass = 8 mol * 6.94 g/mol

Mass = 55.52 g