AP EAMCET2009ChemistryStructure of Atom
Electrons with a kinetic energy of 6.023 10^4 ~J / mol are evolved from the surface of a metal, when it is exposed to radiation of wavelength of 600 ~nm . The minimum amount of energy required to remove an electron from the metal atom is
Options
- A2.3125 10⁻¹⁹ ~J
- B3 10⁻¹⁹ ~J
- C6.02 10⁻¹⁹ ~J
- D6.62 10⁻³⁴ ~J
Correct answer
A. 2.3125 10⁻¹⁹ ~J
Step-by-step solution
aligned & 1 ~mol =6.023 10²³ atoms & KE of 1 ~mol =6.023 10^4 ~J & or KE of 6.023 10²³ atoms & =6.023 10^4 ~J & KE of 1 atom = 6.023 10^4 6.023 10²³ & =1.0 10⁻¹⁹ ~J & h v_ energy = h c = 6.626 10⁻³⁴ 3 10^8 600 10⁻⁹ & =3.313 10⁻¹⁹ ~J & aligned Minimum amount of energy required to remove an electron from the metal ion (ie, Threshold energy) aligned & =h v- KE & =3.313 10⁻¹⁹-1.0 10⁻¹⁹ & =2.313 10⁻¹⁹ ~J aligned