Answer:
37
20
C
a
→
37
19
K
+
0
+
1
e
This equation shows us the parent atom, which is calcium-37. The mass number is written above the atomic number for the atom. The arrow indicates the decay process with the products to the right of the arrow. The products are an atom of potassium-37 and a positron, which is similar to an electron but it carries a charge of +1 instead of a charge of -1. We can see that the transition of a proton to a neutron in positron decay decreases the atomic number of the atom from 20 to 19, but the mass number of 37 remains the same.
Explanation: