What is the mass of 2.542 × 1026 atoms of F?

7.98 × 10^3grams.

Explanation:

To find the mass of fluorine in the number of atoms provided, we first divide the number of atoms by Avagadros number (6.02 × 10^23atoms) to get the number of moles in the fluorine atom. That is;

number of moles (n) = number of atoms (nA) ÷ 6.02 × 10^23 atoms

n = 2.542 × 10^26 ÷ 6.02 × 10^23

n = 0.42 × 10^ (26-23)

n = 0.42 × 10^3

n = 4.2 × 10^2moles

Using mole = mass ÷ molar mass

Molar/atomic mass of fluorine (F) = 19g/mol

mass = molar mass × mole

Mass (g) = 19 × 4.2 × 10^2

Mass = 79.8 × 10^2

Mass = 7.98 × 10^3grams.