Question

Calculate the number of atoms in each of the following: 1) 52 moles of He 2) 52 amu of He 3) 52g of He

Answer 1

1) 1 mole of He contains 6.023x10^23
52 moles of He contains 52 x 6.023 x10^23

2) Atomic mass of Helium is 4u = 2protons + 2 Neutrons = 1 atom 
No. of atoms in 52u = 52/4 = 13 atoms

3) 4g of He has 1 mole 
1g of He has 1/4 mole 
52g of He has 1/4x52 = 13 moles 

1 mole=6.022x10^23atoms 
so 13 moles means 13x6.023x10^23

Answer 2

Answer:

1) 1 mole of He contains 6.023x10^23

52 moles of He contains 52 x 6.023 x10^23

2) Atomic mass of Helium is 4u = 2protons + 2 Neutrons = 1 atom 

No. of atoms in 52u = 52/4 = 13 atoms

3) 4g of He has 1 mole 

1g of He has 1/4 mole 

52g of He has 1/4x52 = 13 moles 

1 mole=6.022x10^23atoms 

so 13 moles means 13x6.023x10^23