I dont understand , what u write
Answer is valence electron, they all have total of 2 valence electron.
remember group number = valence electron
Your answer is x= 1/2, this is because to get the x alone you need to move the 2 so you divide 2x by to and you have to do the same to the other side so 1/2, and you get x=1/2
I think that's called "Trajectory"