Answer
(a) X = $^{23}_{11}Na$
(b) X = $^1_1H$
(c) X = $^1_0n$
(d) X = $^{56}_{26}Fe$
(e) X = $^{0}_{-1}\beta$
Work Step by Step
1. Find the atomic number of X:
(a) 12 + 1 = 2 + x
x = 11
X = Na
(b) 27 + 1 = 27 + x
x = 1
X = H
(c) 92 + 0 = 36 + 56 + 3x
3x = 0
x = 0
X = n
(d) 24 + 2 = 0 + x
x = 26
X = Fe
(e) 8 = 9 + x
x = -1
X = $\beta$
2. Find the atomic mass of X:
(a) 26 + 1 = 4 + x
x = 23
(b) 59 + 2 = 60 + x
x = 1
(c) 235 + 1 = 94 + 139 + 3x
3x =3
x = 1
(d) 53 + 4 = 1 + x
x = 56
(e) 20 = 20 + x
x = 0