Question 30

Question

Sodium undergoes beta decay. Match the missing parts (A, B, and C) of the nuclear equation above to their correct number or symbol:
24/11 Na -> 0/-1 e +A/B c
Column A
1.
A:
A
2.
B:
B
3.
C:
C
Column B
a.25
b.24
c.10
d.Mg
e.23
f.12
g.Ne

Answer 1

In beta decay, a neutron in the nucleus of an atom is transformed into a proton, which results in the emission of a beta particle (an electron). For the given nuclear equation for sodium (Na), the process will look like this:

\[ ^{24}{11}Na \rightarrow ^{A}{B}C + ^{0}_{-1}e \]

Here, after beta decay:

• The atomic number (Z) will increase by 1 because a neutron turns into a proton. Thus:
  • The original atomic number of Na is 11, so the new atomic number will be 12 (which corresponds to magnesium, Mg).
• The mass number (A) remains the same because a neutron is converting to a proton without changing the total number of nucleons.

So we write the decay as: \[ ^{24}{11}Na \rightarrow ^{24}{12}Mg + ^{0}_{-1}e \]

Now we can fill in the missing parts:

• A: 24 (the mass number remains the same)
• B: 12 (the new atomic number corresponds to magnesium)
• C: Mg (the element formed after beta decay)

Thus, the correct matches are:

1. A: b (24)
2. B: f (12)
3. C: d (Mg)

Final Answers:

1. A: b (24)
2. B: f (12)
3. C: d (Mg)