Join the IDNLearn.com community and get your questions answered by knowledgeable individuals. Join our community to receive prompt and reliable responses to your questions from experienced professionals.
Answer:
Explanation:
β decay is a process in which a nucleus emits an electron.
The nuclear symbol for a β particle is
l
0
-1
e
.
In any nuclear equation, the sum of the subscripts (atomic numbers,
Z
) and the sum of the superscripts (atomic masses,
M
) must be equal on each side of the equation.
For the β decay of iodine 131, we have
131
53
I
→
l
M
Z
X
+
l
0
-1
e
Hence
131
=
M
+
0
, so
M
=
131
53
=
Z - 1
, so
Z
=
53
+
1
=
54
The element
X
with
Z = 54
is
Xe
.
So the equation is
131
53
I
→
131
54
Xe
+
l
0
-1
e
Note that in β decay, the product has the same mass number but an atomic number that has increased by 1.