Find in the no. of molecules in the following substances.
a. 8g Helium
b. 4 mole Helium

Explanation

a) mass of grams = 8g
Atomic mass of Helium = 4
No. of atoms in 8g Helium
`=(8/4) xx 6.022x 10^23 = 12.044 xx10^23`
b) No.of atoms In.1 mole of Helium = `6.022x10^23`
No. of atoms in 4 mole of Helium= `4x6.022x10^23`