#### Practice

What is the maximum number of electrons that can occupy one p orbital?

a.14

b. 2

c. 10

d.1

e. 6

b. 2

The n = 2 shell can accommodate a maximum of ____ electrons.

A. 10

B. 8

C. 4

D. 6

E. 2

B.8

Which of the following is an incorrect orbital occupancy representation?

- 4d
^{3} - 3d
^{5} - 2s
^{3} - 1s
^{1} - 2p
^{2}

C. 2s^{3}

The maximum number of electrons that can be accommodated in 3s subshell is

- 10
- 2
- 6
- 1
- 8

B. 2

The following electron configuration is incorrect according to the Pauli exclusion principle:

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

B. 1s^{2}2s^{3}2p^{3}

Which electron configuration represents an excited state of the indicated atom?

**He**: 1s^{2}**Na**: 1s^{2}2s^{2 }2p^{6}3s^{2}3p^{2}3s^{1}**P**: 1s^{2}2s^{2}2p^{6}3s^{2 }3p^{3}**N**: 1s^{2}2s^{2 }2p^{2}3s^{1}**Ne**: 1s^{2}2s^{2}2p^{6}

D. N: 1s^{2} 2s^{2 }2p^{2}3s^{1}

This element is in the p-block of the periodic table

- Cs
- In
- Pd
- He
- Po

B. In

Which of the following represents the ground state electron configuration of a transition element?

- 1s
^{2}2s^{2}2p^{6}3s^{2}3p^{5} - 1s
^{2}2s^{2}2p^{6}3s^{2}3p^{6}3d^{10}4s^{1} - 1s
^{2}2s^{2}2p^{6}3s^{2}3p^{6}3d^{10}4s^{2}4p^{4} - 1s
^{2}2s^{2}2p^{6}3s^{2}3p^{6}4s^{2} - 1s
^{2}2s^{2}2p^{3}

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

Which of the following is the correct ground-state electron configuration of V is?

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

E. 1s^{2}2s^{2}2p^{6}3s^{2}3p^{6}4s^{2}3d^{3}

Which of the following represents a possible excited-state electron configuration for an iron atom?

- [Ar]3d
^{7}4s^{2} - [Ar]3d
^{6}4s^{2} - [Ar]3d
^{7}4s^{1} - [Ar]3d
^{6}4s^{1} - [Kr]3d
^{7}4s^{1}

C. [Ar]3d^{7}4s^{1}

Each of the following is an accurate representation of ground-state electron configuration except:

**Fe**: [Ar]4s^{2}3d^{6}.**Ca**: [Ar]4s^{2}.**Se**: [Ar] 4s^{2}3d^{10}4p^{4}.**Ag**: [Kr] 5s^{2}4d^{9}.**Ti**: [Ar] 4s^{2}3d^{2}

D. **Ag**: [Kr] 5s^{2}4d^{9}.

How many electrons, in total, are present in p orbitals in a ground-state nickel atom?

- 8
- 12
- 6
- 24
- 3

B. 12

Which one of the following represents electron configuration of an excited carbon atom?

- 1s
^{2}2s^{2}2p^{3} - 1s
^{2}2s^{2}2p^{1} - 1s
^{2}2s^{2}2p^{1}3s^{1} - 1s
^{2}2s^{2}3s^{1} - 1s
^{2}2s^{2}2p^{2}

C. 1s^{2}2s^{2}2p^{1}3s^{1}

Which of the following ground-state electron configurations is incorrect?

**Cl**: [Ne]3s^{2}3p^{5}**Ge**: [Ar] 4s^{2 }3d^{10}3p^{2}**Co**: [Ar]4s^{2}3d^{7}**Rb**: [Kr]5s^{1}**Mn**: [Ar] 4s^{2}3d^{5}

B. Ge: [Ar]4s^{2 }3d^{10}3p^{2}

Bromine atom has ___ valence electrons.

- 6
- 4
- 7
- 5
- 35

C. 7

What is the ground-state electron configuration of chromium (Cr)?

- 1s
^{2}2s^{2}2p^{6}3s^{2}3p^{6}3d^{10}4s^{2}4p^{6}4d^{10}5s^{2}5p^{4} - 1s
^{2}2s^{2}2p^{6}3s^{2}3p^{6}4s^{1}3d^{5} - 1s
^{2}2s^{2}2p^{6}3s^{2}3p^{6}3d^{10} - 1s
^{2}2s^{2 }2p^{6}3s^{2}3p^{6}4s^{2}3d^{4} - 1s
^{2}2s^{2}2p^{6}3s^{2}3p^{6}3d^{6}

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

What is the ground-state electron configuration of bromine (Br)?

- 1s
^{2}2s^{2}2p^{6}3s^{2}3p^{6}4s^{1}3d^{10 }4p^{5} - [Kr] 4s
^{2}3s^{10}4p^{5} - [Ne] 3s
^{2}3p^{5} - [Ar] 4s
^{2}3d^{10}4p^{5} - 1s
^{2}2s^{2}2p^{5}3s^{2}3p^{6}4s^{2}3d^{10}4p^{5}

D. [Ar] 4s^{2}3d^{10}4p^{5}

The ground state electron configuration of As is ________.

- 1s
^{2}2s^{2}3s^{2}3p^{6}4s^{2}3d^{10}4p^{2} - 1s
^{2}2s^{2}2p^{6}3s^{2}3p^{6}4s^{2}3d^{10}4p^{1} - 1s
^{2}2s^{2}2p^{6}3s^{2}3p^{6}4s^{2}3d^{10}4p^{3} - 1s
^{2}2s^{2}2p^{6}3s^{2}3p^{6}4s^{2}3d^{10}4d^{3} - [Kr]4s
^{2}3d^{10}4d^{3}

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

Which of the following elements has the same valence-shell electron configuration as lithium?

- calcium.
- sulfur.
- potassium.
- magnesium.
- argon.

C. potassium

How many unpaired electrons are found in the d orbital of nickel.

- 4 electrons
- 3 electrons
- 2 electrons
- 8 electrons
- none of these

C. 2 electron

The ground-state electron configuration of the element ________ is [Kr]5s^{2}4d^{10}

- Fe
- Cd
- Cr
- Mn
- Zn

B. Cd

The ground-state electron configuration of ________ is [Ar]4s^{2}3d^{7}.

- Ti
- Co
- Fe
- Cr
- Cs

B. Co

Chlorine has the following ground-state configuration:

- [He]3s
^{2}3p^{2} - [Ne]3s
^{2}3p^{5} - [He]2s
^{2}2p^{5} - [Ne]2s
^{2}2p^{3} - [He]3s
^{2}3p^{5}

B.[Ne]3s^{2}3p^{5}

What is the maximum number of electrons that can be accommodated in each d-subshell?

- 10
- 5
- 6
- 3
- 2

A.10

The 3p subshell of a sulfur atom contains ________ electrons.

- 16
- 8
- 2
- 4
- 6

D. 4

What noble gas core should be used when writing the condensed electron configuration of Strontium (Sr)?

- [Xe]
- [Kr]
- [Ne]
- [Ar]
- [He]

B. [Kr]

# Electron Configuration of Ions

Which of the following is the ground state electron configuration of S^{2-}?

A) [Ne]

B) [Ne]3s^{2}3p^{6 }C) [Ne]3s^{2}3p^{4 }D) [Ne]3s^{2}3p^{2 }E) [Ne]4s^{2}

B) [Ne]3s^{2}3p^{6 }

A cation of +3 indicates that an element has

A) lost three neutrons.

B) lost three protons.

C) lost three electrons.

D) gained three protons.

E) gained three electrons.

C) lost three electrons.

Indicate the ground state electron configuration for Cl⁻.

A) 1s^{2}2s^{2}2p^{6}3s^{2}3p^{4 }B) 1s^{2}2s^{2}2p^{6}3s^{2}3p^{5 }C) 1s^{2}2s^{2}2p^{6}3s^{2}3p^{6 }D) 1s^{2}2s^{2}2p^{6}3s^{1}3p^{6 }E) 1s^{2}2s^{2}2p^{6}3s^{3}3p^{5}

C) 1s^{2}2s^{2}2p^{6}3s^{2}3p^{6 }

Which of the following is the ground state electron configuration of Ba^{2+ }?

A) [Kr]5s^{2}4d^{10}5p^{6}6s^{2 }B) [Kr]5s^{2}4d^{10}5p^{6 }C) [Kr]5s^{2}4d^{10}5p^{6}5d^{2 }D) [Kr]5s^{2}5p^{6 }E) [Kr]5s^{2}4d^{10}5p^{6}6s^{2}

B) [Kr]5s^{2}4d^{10}5p^{6 }

Which of the following is the ground state electron configuration of Ti^{2⁺}.

A) [Ar]3d^{4 }B) [Ar]3d^{2 }C) [Ar]4s^{2 }D) [Ar]4s^{2}3d^{4 }E) [Ar]4s^{2}3d^{2}

B) [Ar]3d^{2 }

Which of the following is the ground state electron configuration of Zn^{2⁺}?

A) [Ar]4s^{2}3d^{6 }B) [Ar]3d^{10 }C) [Ar]4s^{2}3d^{8 }D) [Ar]3d^{8 }E) [Ar]

B) [Ar]3d^{10 }

Which of the following is the ground state electron configuration of Cr^{3⁺}?

A) [Ar]

B) [Ar]4s^{1}3d^{2 }C) [Ar]3d^{3 }D) [Ar]4s^{2}3d^{1 }E) [Ar]4s^{2}3d^{7}

C) [Ar]3d^{3 }

How many valence electrons are present in the azide (N^{3-}) ion?

A) 3

B) 5

C) 8

D) 7

E) 2

C) 8

Ca^{2+} has the following ground state electron configuration:

A) 1s^{2}2s^{2}2p^{6 }B) 1s^{2}2s^{2}2p^{6}3s^{2 }C) 1s^{2}2s^{2}2p^{6}3s^{2}3p^{2 }D) 1s^{2}2s^{2}2p^{6}3s^{2}3p^{6}4s^{2}3d^{2 }E) 1s^{2}2s^{2}2p^{6}3s^{2}3p^{6}

E) 1s^{2}2s^{2}2p^{6}3s^{2}3p^{6}

Rb+ has the following ground state electron configuration:

A) [Kr]5s^{2}4d^{6 }B) [Kr]4s^{2 }C) [Ar]4s^{2}4p^{4 }D) [Kr]5s^{1 }E) [Ar]4s^{2}3d^{10}4p^{6}

E) [Ar]4s^{2}3d^{10}4p^{6}^{ }

Which of the following is the ground state electron configuration of Fe^{3⁺}?

A) [Ar]3d^{5}** ^{ }**B) [Ar]4s

^{1}3d

^{3 }C) [Ar]

D) [Ar]4s

^{2}3d

^{9 }E) [Ar]4s

^{2}3d

^{1}

A) [Ar]3d^{5}^{ }

The correct ground state electron configuration for Br^{–} is:

A) [Ar]4s^{2}3d^{10}4p^{6 }B) [Ar]4s^{2}3d^{10}4p^{3 }C) [Ar]4s^{2}3d^{8}4p^{6 }D) [Ar]4s^{2}3d^{10}4p^{5 }E) [Ar]4s^{2}4p^{6}

A) [Ar]4s^{2}3d^{10}4p^{6 }

How many electrons are present in the ground state of Mg^{2+} ion?

A) 2

B) 6

C) 10

D) 8

E) 12

C) 10