How much does 1.5 x 10" atoms of neon weigh?

5.027 * 10^-12 g

Explanation:

Assuming the number of atoms given is;

1.5 * 10^11 atoms of Neon

We can get the mass of the atoms given;

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

In this case;

1 mole of Ne contains 6.022 * 10^23 atoms Therefore, to get the mass of the atoms given; Molar mass of Ne is 20.18 g/mol

Therefore;

20.18 g contains 6.022 * 10^23 atoms

Thus;

Mass = (20.18 g * 1.5 * 10^11 atoms) : 6.022 * 10^23 atoms

= 5.027 * 10^-12 g

Therefore, 1.5 * 10^11 atoms of Neon contains a mass of 5.027 * 10^-12 g