Electron Configuration - Basic introduction-

How many electrons does an atom of Nitrogen have?

• 5

• 8

• 6

• 7

What is the Electron Configuration for an atom of Aluminum?

• 1s2 2s2 2p6 3s2 3p1

• 1s2 2s2 2p6 3s2 3p6

• 1s2 2s2 2p6 3s2 3p5

• 1s2 2s2 2p6 3s2 3p3

How many electrons does the Fe 2+ ion have?

• 25

• 24

• 27

• 26

Answer explanation

The Fe 2+ ion has two fewer electrons than a neutral Fe atom, for a total of 24 electrons^.

It loses 2 electrons that is why it becomes more positive.

Therefore, its electron configuration will have 24 electrons in the following orbitals:

1s2 2s2 2p6 3s2 3p6 3d6

or the same as Argon's electronic configuration [Ar] 3d6.

The goal of all elements is to be like the Noble Gases-to be stable and have 8 valence electrons. (Octet Rule)

What is the Electron Configuration for the Fe?

• 1s2 2s2 2p6 3s2 3p6 4s2 3d8

• 1s2 2s2 2p6 3s2 3p6 4s2 3d4

• 1s2 2s2 2p6 3s2 3p6 4s2 3d10

• 1s2 2s2 2p6 3s2 3p6 4s2 3d6

What is the Electron Configuration for the Chloride ion?

• 1s2 2s2 2p6 3s2 3p7

• 1s2 2s2 2p6 3s2 3p5

• 1s2 2s2 2p6 3s2 3p8

• 1s2 2s2 2p6 3s2 3p6

Answer explanation

Chlorine has the atomic number 17.

However, chloride ion has 18 electrons.

It "wants" one more electron for it to be stable.

So it attains the electronic configuration of argon(atomic number 18)

1s2 2s2 2p6 3s2 3p6.

How many electrons does an atom of Iron have?

• 25

• 27

• 24

• 26

What is the Electron Configuration for an atom of Nitrogen?

• 1s2 2s2 2p3

• 1s2 2s2 2p4

• 1s2 2s2 2p5

• 1s2 2s2 2p6

What is the Electron Configuration for an atom of Chlorine?

• 1s2 2s2 2p6 3s2 2p5

• 1s2 2s2 2p5

• 1s2 2s2 2p3

• 1s2 2s2 2p4

How many electrons does the Aluminum ion have?

• 14

• 13

• 15

• 10

Answer explanation

An aluminum ion (Al$^{3+}$) is an atom of aluminum that has lost three electrons. The number of electrons in an atom is equal to the number of protons, which is the atomic number of the element. The atomic number of aluminum is 13, so a neutral aluminum atom has 13 electrons. To find the number of electrons in an aluminum ion, we need to subtract the number of electrons that were lost from the original number of electrons. Therefore, an aluminum ion has 13 - 3 = 10 electrons

What is the Electron Configuration for the Aluminum ion?

• 1s2 2s2 2p6 3s2

• 1s2 2s2 2p6

• 1s2 2s2 2p6 3s2 3p2

• 1s2 2s2 2p6 3s2 3p3

Answer explanation

The electron configuration for the aluminum ion (is the same as the noble gas neon (Ne).

or [Ne] in shorthand notation. This is because aluminum loses three electrons from its valence shell to form a positive ion with a stable octet configuration¹².