Question

Why are all diatomic molecules diatomic molecules linear, regardless of the number of valence electron pairs on the atom?

i don't understand this question

what is meant by linear?

Answer 1

Linear means that the atoms lie on a straight line. You can't draw H-H, N-N, O-O, F-F, Cl-Cl, Br-Br, etc any other way than a straight line. Of course you can draw them as
H
|
H
or as
Cl
|
Cl
BUT that's still a straight line.