K+ (atomic number = 19)
The neutral atom would have an electronic arrangement of 2,8,8,1.
It loses one electron (to make it one-positive)
Consequently, the ion has an arrangement of 2,8,8,0
F- (atomic number = 9)
The neutral atom would have an electronic arrangement of 2,7.
It gains one electron (to make it one-negative)
Consequently, the ion has an arrangement of 2,8
O2- (atomic number = 8)
The neutral atom would have an electronic arrangement of 2,6.
It gains two electrons (to make it two-negative)
Consequently, the ion has an arrangement of 2,8
