Question

How many atoms of gold (Au) are present in a sample of 2.5 mol Au?

1.5 × 10^24 atoms Au

1.5 × 10^23 atoms Au

4.2 × 10^24 atoms Au

4.2 × 10^23 atoms Au

Answer 1

1 mole of any element=6.022*10²³ atoms
2.5 moles of Au=2.5(6.022*10²³ atoms)=1.5*10²⁴ atoms

answer: 1.5 x 10²⁴ atoms Au.