In this post, the user has provided a series of Imp MCQ questions on Electron Configuration related to the electronic configurations of different atoms and ions. The questions cover topics such as the number of valence electrons in an atom, the electronic configuration of ions such as Cr+, Cu+, Cu2+, Cl-, and K+, the outermost principle quantum number of Fe, the subshell in which the valence electron enters in Fe, the maximum number of electrons in a d subshell and the subshells that exist in an atom. Additionally, the questions also cover the number of orbitals in different subshells such as p, d, and f, and which elements provide evidence for the 4f and 3d subshells in the periodic table.

1.How many valence electrons are present in an atom of an element with atomic number 19?

A. 2

B. 4

C. 9

D. 1

2.What is the correct electronic configuration of Cr^{+} ion?

**1s**^{2}**2s**^{2}**2p**^{6}**3s**^{2}**3p**^{6}**4s**^{1}**3d**^{5}

**1s**^{2}**2s**^{2}**2p**^{6}**3s**^{2}**3p**^{6}**4s**^{2}**3d**^{4}

**1s**^{2}**2s**^{2}**2p**^{6}**3s**^{2}**3p**^{6}**4s**^{0}**3d**^{5}

**1s**^{2}**2s**^{2}**2p**^{6}**3s**^{2}**3p**^{6}**4s**^{1}**3d**^{4}

3.What is the correct electronic configuration of Cu^{+} ion?

**1s**^{2}**2s**^{2}**2p**^{6}**3s**^{2}**3p**^{6}**4s**^{1}**3d**^{10}

**1s**^{2}**2s**^{2}**2p**^{6}**3s**^{2}**3p**^{6}**4s**^{2}**3d**^{9}

**1s**^{2}**2s**^{2}**2p**^{6}**3s**^{2}**3p**^{6}**4s**^{0}**3d**^{10}

**1s**^{2}**2s**^{2}**2p**^{6}**3s**^{2}**3p**^{6}**4s**^{1}**3d**^{10}

4.What is the correct electronic configuration of Cu^{2+} ion?

**1s**^{2}**2s**^{2}**2p**^{6}**3s**^{2}**3p**^{6}**4s**^{1}**3d**^{5}

**1s**^{2}**2s**^{2}**2p**^{6}**3s**^{2}**3p**^{6}**4s**^{2}**3d**^{4}

**1s**^{2}**2s**^{2}**2p**^{6}**3s**^{2}**3p**^{6}**4s**^{0}**3d**^{5}

**1s**^{2}**2s**^{2}**2p**^{6}**3s**^{2}**3p**^{6}**4s**^{1}**3d**^{4}

5.What is the correct electronic configuration of Cl^{–} ion?

**1s**^{2}**2s**^{2}**2p**^{6}**3s**^{1}**3p**^{6}**1s**^{2}**2s**^{2}**2p**^{6}**3s**^{2}**3p**^{5}**1s**^{2}**2s**^{2}**2p**^{6}**3s**^{2}**3p**^{6}**1s**^{2}**2s**^{2}**2p**^{6}**3s**^{2}**3p**^{5}**4s**^{1}

6.How many electrons are there in K^{+} ion?

A. 20

B. 12

C. 19

D. 18

7.What is the outermost principle quantum number of Fe?

- 3
- 4
- 5
- 6

8.In which subshell the valence electron enters in Fe?

- 3s
- 4s
- 3d
- 3p

9.Which subshell can possibly exist in an atom?

- 2d
- 3f
- 3d
- 1p

10.How many orbitals does p subshell consists of?

- 6
- 1
- 3
- 5

11.How many orbitals does d subshell consists of?

- 6
- 1
- 3
- 5

12.How many orbitals does f subshell consists of?

- 6
- 1
- 7
- 5

13.How many maximum electrons can d subshell possess?

- 6
- 5
- 10
- 14

14.Which elements provides the evidence for the 4f subshell in the periodic table?

- Transition elements
- Halogens
- Actinoids
- Lanthanoids

15.Which elements provides the evidence for the 3d subshell in the periodic table?

- Halogens
- Actinoids
- Lanthanoids
- Transition elements

I hope you will be able to solve Imp MCQ questions on Electron Configuration. If need guidance, write in the comments.

Check MCQ on Stoichiometric relationships

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