Two elements represents by the letter Q and R atomic number 9 and 12 respectively. 1. Write the electronic configuration of R
2. To what group does Q belongs to in the periodic table
3. Write the formula of the compound formed when Q combines with R

The two elements with atomic number 9 and 12 are represented by letter Q and R respectively, where Q represents fluorine atom and R represents magnesium atom.

1. Electronic configuration of R that is magnesium (atomic number 12) is:

1s2 2s2 2p6 3s2

2. Q represents fluorine atom, which belongs to group 17 in periodic table that is the most reactive and lightest member of the group.

3. Q and R that is fluorine and magnesium combinely form magnesium fluoride or MgF2.

the atomic mass is the bottom number on the element.

-steel jelly

i'm assuming that it's c.) red bank..