Answer:
a. AB
b.11=group 1
9=group 7
Explanation:
A=11
B=9
When they combine, that's
A+B=AB
According to the chemistry, element with atomic number 11 is sodium and element with atomic number of 9 is fluorine
So when they come it will give NaF
B.Na=11
=2,8,1
It belongs to group 1
F=9
=2,7
It belongs to group 7
When they combine by form ionic bond
