Answer:
4.13×10^22 atoms
Explanation:
1. Find number of moles
mole=mass/rmm of compound
mole= 3.50/102
mole= 7/204 mol
2. Multiply it with avagadros constant( 6.02×10^23 particles)
7/204 × 6.02×10^23= 2.0657×10^22
3. Multiply it with the number of ALMINIUM ATOMS IN AL203( which is 2 atoms)
2.0657×10^22 × 2
you get 4.13×10^22 atoms
