Question

Find the number of atoms in 7.85 g of aluminum

Answer 1

MM(Al) = 26.98 g/mol

n(Al) $= \frac{7.85}{26.98}= 0.29 \;mol$

A mole of Al contains 6.02×10²³ atoms.

N(atoms)$= 0.29 \times 6.2 \times 10^{23}=1.8 \times 10^{23} \; atoms$