Question

Threshold energy of metal is 2.8ev if radiation is 2500angstrom fall on metal what is kinetic energy of metal

Answer 1

ANSWER

E=hv=

λ

hc

=

4000×10

−10

6⋅63×10

−34

×3×10

8

=4×966×10

−19

J

=

1⋅6×10

−19

4⋅966×10

−19

eV=3⋅103eV

Energy of emitted photon =(3⋅103−2⋅5)eV

=0⋅603eV