+244 A metal having a work function of 1.2 eV has light whose photon energy is 3.6 eV shining on it. What is maximum possible kinetic energy of the electrons that are ejected?
A.5.4 × 10-19 J
B.3.8 x 10-19 J
C.4.9 × 10-19 J
D.5.8 x 10-19 J J
E.4.4 × 10-19 J
A metal having a work function of 1.2 eV has light whose photon energy is 3.6 eV shining on it. What is maximum possible kinetic energy of the electrons that are ejected?
A.5.4 × 10-19 J
B.3.8 x 10-19 J
C.4.9 × 10-19 J
D.5.8 x 10-19 J J
E.4.4 × 10-19 J
It takes 1.2 eV to eject the electron, so of the 3.6 eV energy from the photon 3.6eV−1.2eV=2.4eV will go into the kinetic energy of the ejected electron. Next we convert from eV to Joules: 1eV=1.6022x10−19J, so the ejected electron will have kinetic energy
KE=2.4eV=3.8×10−19J.
Choose answer B.
