Which of the following statements are correct?
(A) The electronic configuration of Cr is [Ar] 3d5 4s1.
(B) The magnetic quantum number may have a negative value.
(C) In the ground state of an atom, the orbitals are filled in order of their increasing energies.
(D) The total number of nodes are given by n $-$ 2.
Choose the most appropriate answer from the options given below :
Solution
<p>(A) Cr (24) = 1s<sup>2</sup> 2s<sup>2</sup> 2p<sup>6</sup> 3s<sup>2</sup> 3p<sup>6</sup> 3d<sup>5</sup> 4s<sup>1</sup></p>
<p>= [Ar] 3d<sup>5</sup> 4s<sup>1</sup></p>
<p>(B) Magnetic quantum number (m) values ranging from $-$ l to + l including zero.</p>
<p>$\therefore$ It can have negative value.</p>
<p>(C) According to Aufbau rule, electrons are filled first in these orbitals which have low energy.</p>
<p>$\therefore$ Statement C is correct.</p>
<p>(D) We know,</p>
<p>Number of Radial nodes = n $-$ l $-$ 1</p>
<p>and number of Angular nodes = l</p>
<p>$\therefore$ Total nodes = n $-$ l $-$ 1 + 1 = n $-$ 1</p>
About this question
Subject: Chemistry · Chapter: Atomic Structure · Topic: Bohr's Model
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