Indicate the number of unpaired electrons in:

The bromine atom possesses 35 electrons. It contains 6 electrons in 2p orbital, 6 electrons in 3p orbital and 5 electrons in 4p orbital. Which of these electron experiences the lowest effective nuclear charge?

Class 11 Chemistry Structure of Atom View Answer

The quantum numbers of six electrons are given below. Arrange them in order of increasing energies.

The quantum numbers of six electrons are given below. Arrange them in order of increasing energies. If any of these combination(s) has/have the same energy lists:

1. n = 4, l = 2, \( m_l\) = –2 , ms = \( -\dfrac{1}{2}\)

2. n = 3, l = 2, \( m_l\)= 1 , ms = \( +\dfrac{1}{2}\)

3. n = 4, l = 1, \( m_l\) = 0 , ms = \( +\dfrac{1}{2}\)

4. n = 3, l = 2, \( m_l\)= –2 , ms = \( -\dfrac{1}{2}\)

5. n = 3, l = 1, \( m_l\) = –1 , ms= \( +\dfrac{1}{2}\)

6. n = 4, l = 1, \( m_l\) = 0 , ms = \( +\dfrac{1}{2}\)

Class 11 Chemistry Structure of Atom View Answer

Accepted Answer

Solution :-

(a) Phosphorus (P):

The atomic number of phosphorus is 15

Electronic configuration of Phosphorus:

1s² 2s ² 2p ⁶ 3s ² 3p ³

This can be represented as follows:

From the diagram, it can be observed that phosphorus has three unpaired electrons.

(b) Silicon (Si):

The atomic number of Silicon is 14

Electronic configuration of Silicon:

1s ² 2s ² 2p ⁶ 3s ² 3p ²

This can be represented as follows:

From the diagram, it can be observed that silicon has two unpaired electrons.

(c) Chromium (Cr):

The atomic number of Cr is 24

Electronic configuration of Chromium:

1s ² 2s² 2p⁶ 3s ² 3p ⁶ 4s ¹ 3d ⁵

This can be represented as follows:

From the diagram, it can be observed that chromium has six unpaired electrons.

(d) Iron (Fe):

The atomic number of iron is 26

Electronic configuration of Fe:

1s ² 2s² 2p ⁶ 3s ² 3p ⁶ 4s ² 3d ⁶

This can be represented as follows:

From the diagram, it can be observed that krypton has no unpaired electrons.

Answered by Pragya Singh | 1 year ago