How many moles are there in 50.5 atoms ba

8.386 * 10^-23 moles

Explanation:

We are given;

Number of atoms of Ba is 50.5 atoms

We are required to determine the number of moles

We need to know that 1 mole of an element contains atoms equivalent to the Avogadro's number, 6.022 * 10^23. Therefore, 1 mole of an element contains 6.022 * 10^23 atoms

In this case;

1 mole of Ba contains 6.022 * 10^23 atoms

Number of moles = 50.5 atoms : 6.022 * 10^23 atoms

= 8.386 * 10^-23 moles

The number of moles in 50.5 atoms of Ba is 8.386 * 10^-23 moles