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ololo11 [35]
3 years ago
12

Which of these pairs of elements have the same number of valence electrons?

Chemistry
2 answers:
Nezavi [6.7K]3 years ago
5 0

Answer : The correct option is, (B) sodium and potassium

Explanation :

Valence electrons : Valence electrons are those electrons which are present in the outermost shell of the element.

As we know that,

<u>Option (A) :</u>

Element = Hydrogen

Atomic number = Number of electrons = 1

The electronic configuration is, 1s^1

The number of valence electrons = 1

Element = Helium

Atomic number = Number of electrons = 2

The electronic configuration is, 1s^2

The number of valence electrons = 2

<u>Option (B) :</u>

Element = Sodium

Atomic number = Number of electrons = 11

The electronic configuration is, 1s^22s^22p^63s^1

The number of valence electrons = 1

Element = Potassium

Atomic number = Number of electrons = 19

The electronic configuration is, 1s^22s^22p^63s^23p^64s^1

The number of valence electrons = 1

<u>Option (C) :</u>

Element = Carbon

Atomic number = Number of electrons = 6

The electronic configuration is, 1s^22s^22p^2

The number of valence electrons = 4

Element = Oxygen

Atomic number = Number of electrons = 8

The electronic configuration is, 1s^22s^22p^4

The number of valence electrons = 6

<u>Option (D) :</u>

Element = Boron

Atomic number = Number of electrons = 5

The electronic configuration is, 1s^22s^22p^1

The number of valence electrons = 3

Element = Beryllium

Atomic number = Number of electrons = 4

The electronic configuration is, 1s^22s^2

The number of valence electrons = 2

From this we conclude that, the sodium and potassium are the elements have the same number of valence electrons.

Hence, the correct option is, (B)

KatRina [158]3 years ago
3 0
B) sodium and potassium (1 valence electron)
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