Question

an element has 12 atomic number and B has 8 atomic numbers what type of Bond they have and why

Answer 1

Atomic number-12
Magnesium
Atomic number -8
Oxygen
So the bond between a metal and non metal is electrovalent
Bond as there is share of electrons.

Answer 2

Hi.

Here is your answer---

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Let the elements with atomic number 12 be A.

Thus,
Electronic Configuration of A = 2,8,2
Valency = 2
Charge = 2+
Thus, it is metal.

Electronic Configuration of B = 2,6
Valency = 2
Charge = 2-
Thus, it is non-metal.

The chemical bond which will be formed between these two is Ionic Or Electrovalent Bond.

Reason---
# The number of Electrons which will be loses by elements A will be completely taken by the Elements B, thus the bond formed will be Ionic.

# Usually the Bond formed between the Metals and Non-Metals are Ionic.

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Hope it helps.

Have a nice day.