What is the only possible value of mℓ for an electron in an s orbital?
express your answer numerically.

The only possible value of mℓ for an electron in an s orbital is 0 (zero).

Explanation:

mℓ is the third quantum number, named magnetic quantum number.mℓ depends on the second quantum number, ℓℓ tells the subshell or kind of orbital (shape) according to this table:

     kind of orbital           ℓ

               s                       0

               p                       1

               d                       2

               f                        3

So, given that your electron is in an s orbital, the only possible value of ℓ is 0.The possible values of mℓ are the integers from - ℓ to + ℓ

This table shows you the possible values of mℓ:

               ℓ           mℓ

               0            0

               1            -1, 0, + 1

               2           -2, -1, 0, +1, +2

               3           -3, -2, -1, 0, +1, +2, +3.

Then, the only possible value of mℓ for an electron in a s orbital is 0.

You can read more about quantum numbers on link.

Yes it would be a physical change.

13) a 14) a15) b16) i don't know sorry17) a (maybe)