Question

What elements form nonpolar covalent bonds?

Answer 1

`"Homonuclear diatomics.........."`; the first 9 elements for a start.

Explanation:

`"Dihydrogen, dihelium cation, dilithium, diberyllium, diboron,"`
`"dicarbon, dinitrogen, dioxygen, difluorine"`.

Now you could only put four of these molecules in a bottle, which ones? However, I think all of these beasts have been observed spectroscopically. For a homonuclear diatomic, as each element is identical and necessarily has the SAME electronegativity, there can no `"bond polarity"`, no unequal sharing of electron density.