One mole of a substance contains 6.02×10∧23 particles,
1 mole of a aluminium contains 27 g
35 g of aluminium contains 35/27 =1.296 moles
Thus, the number of particles will be 1.296 × 6.02 ×10∧23
= 7.804 × 10∧23 particles,
Hence, 35 g of Aluminium contains 7.804 × 10∧23 atoms