Electrons with a kinetic energy of `6.023 xx 10^(4) J//mol are evolved from the surface of a metal, when it is exposed to radiation of wavelength of 600 nmn. The minimum amount of energy required to remove an electron from the metal atom is

Options

A. `2.3125 xx 10^(-19) J`
B. `3 xx10^(-19) J`
C. `6.02 xx10^(-19) J`
D. `6.62 xx 10^(-32)J`

Answer

C

Explanation

Kinetic energy (KE)`=6.023xx10^(4) J//mol`
wavelength `(lambda)=600 nm=600xx10^(-9)`
1 mole `=6.023xx10^(23)`natoms
KE of 1 atom`=(6.023xx10^(1))/(6.023xx^(23))=10^(-19) J`
`therefore E=hv=(hc)/lambda`
`=(6.626xx10^(-34)xx3xx10^(8))/(600xx10^(-19)`
`=3.313xx10^(-19)j`
`therefore` Minimum energy required to remove an electron from the metal atom
`=hv-KE`
`=3,313xx10^(-19)-1xx10^(-19)`
`=2.313xx10^(-19) J`