Answer:
ml= 0
Step-by-step explanation:
The magnetic quantum number usually gives information regarding the directionality of an atomic orbital. The values of the magnetic quantum number ranges between integer values that lie between +l to -l.
However, the n=1 level contains only the 1s orbital which is spherically symmetrical. The s orbital having l=0 also has magnetic quantum number (ml) =0, hence the answer.