Answer
a. Z = 11, n = 12
b. Z = 88, n = 178
c. Z = 82, n = 126
d. Z = 7, n = 7
Work Step by Step
1. Knowing that this form represents "A" and "Z" in these positions: $^A_ZX$. So:
a. Z = 11
b. Z = 88
c. Z = 82
d. Z = 7
2. Number of neutrons (n) = A - Z
a. n = 23 - 11 = 12
b. n = 266 - 88 = 178
c. n = 208 - 82 = 126
d. n = 14 - 7 = 7
