Answer
$2l+1~~$ values of the orbital magnetic quantum number $~m_l~$ are possible.
Work Step by Step
For each value of $l$, the values of $m_l$ can be $~~m_l = 0, \pm 1, \pm 2,...,\pm l$
$2l+1~~$ values of the orbital magnetic quantum number $~m_l~$ are possible.
