The number of water molecules present in a drop of water weighing 0.018g is

Options

A. `6.02 xx 10^26`
B. `6.02 xx 10^23`
C. `6.02 xx 10^20`
D. `6.02 xx 10^19`

Answer

C

Explanation

No. of water molecules in 18 g of water ` = 6.02 xx 10^23 `
No. of water molecules in 0.018 g of water
` = (6.02 xx 10^23)/(18) xx 0.018`
`= 6.02 xx 10^20`