Which of the following is true ?

Options

A. According to Pauli's exclusion principle, no two electrons in an atom can have the same values of quantum numbers `n, l` and `m`.
B. The total energy of an electron in an orbital is half of its potential energy.
C. The speed of an electron in an orbital increases with increase of quantum number `n`.
D. The energy of an electron in an orbital decreases with increase of its quantum number `n`.

Answer

B

Explanation

(b) (a) False. The correct statement is as under : No two electrons in an atom can have the same value of all four quantum number `n, l,m,` and `m_s`.
(b) True. The expressions are
`PE = -(Ze^2)/((4 pi epsilon_0)r)`
`E = KE = PE`
=`(1)/(2) (Ze^2)/((4 pi epsilon_0) r) - (Ze^2)/((4 pi epsilon_0)r)`
=`- (1)/(2) (Ze^2)/((4 pi epsilon_0)r)`
( c) False. The expression of velocity is `v = (1)/(n)` (constant)
(d) False. The expression of energy is `E = - (1)/(n^2)` (constant).