Assuming the mass of the earth as `6.64xx10^(24)`kg Kg and the average mass of the atoms that make up the earth as 40 u ( atomic mass. Unit ) , the number of atoms in the earth is approximately

Options

A. `10^(30)`
B. `10^(40)`
C. `10^(50)`
D. `10^(60)`

Answer

C

Explanation

`M_e = 6.64 xx10^(24) kg`
`n_1u_1 = n_2u_2`
`implies n xx 40 "amu" = 6.64 xx10^(24) kg`
`implies n xx40 xx1.6 xx10^(27) kg = 6.64 xx10^(29) kg`
`n = (6.64xx10^(29))/(40 xx1.6 xx10^(-27))~~10^(50)`