Which nucleus completes the following equation?
A. 299 Np
B. 20Pa
C. 2 Pa
D. - Np

Answer:
Option D. ²³⁹₉₃Np
Explanation:
Let the unknown be ʸₓA.
Thus, the equation becomes:
²³⁹₉₂U —> ⁰₋₁e + ʸₓA
Next, we shall determine the x, y and A. This can be obtained as follow:
92 = –1 + x
Collect like terms
92 + 1 = x
93 = x
x = 93
239 = 0 + y
239 = y
y = 239
ʸₓA => ²³⁹₉₃A => ²³⁹₉₃Np
Thus, the complete equation is:
²³⁹₉₂U —> ⁰₋₁e + ²³⁹₉₃Np