An element of nuclear number A and proton number Z emits an alpha particle from its nucleus. The nucleon number and the proton number of the new element formed are respectively
-
A.
(A – 2) and (Z – 2) -
B.
(A + 4) and (Z + 2) -
C.
(A– 4) and (Z+2) -
D.
(A+ 4) and (Z – 2) -
E.
(A – 4) and (Z – 2)
Correct Answer: Option E
Explanation
Let the element be S and the element formed after emission be X.
(implies ^{A} _{Z}S to ^{4} _{2}He + X)
(therefore X = ^{A – 4} _{Z – 2}X).