Question

The energy of electron is 2.5 eV. When expressed in Joule, it is
(a) 1.6 x 10-19 J
(b) 4.0 x 10-19 J
(c) 3.2 x 10-19 J
(d) 0

April 8, 2024

Answer

(b) 4.0 x 10^-19 J

Reason — Given, energy of electron = 2.5 eV

1 eV = 1.6 x 10 ^-19 J

Hence,

2.5 eV = 2.5 x 1.6 x 10 ^-19 = 4 x 10 ^-19 J

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