Beta Decay Worksheet

Question 1

How do the parent nucleus’s mass number and atomic number change after one beta-minus emission?

1. Mass number stays the same and atomic number increases by 1.
2. Mass number increases by 1 and atomic number stays the same.
3. Mass number decreases by 1 and atomic number decreases by 1.
4. Both numbers decrease by 1.

Question 2

Explain why the daughter nucleus has one fewer neutron even though its mass number stays the same.

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Question 3

A parent nucleus has A = 24 and Z = 11. Find A and Z for the daughter after one beta-minus decay. Show the balances.

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Question 4

Why does beta-minus decay change the identity of the element?

1. The number of protons changes.
2. The number of electrons in the first shell decreases.
3. The mass number doubles.
4. The daughter always gains an electron from the surroundings.

Question 5

Which record produces a magnesium nucleus?

1. P
2. Q
3. R
4. All three

Question 6

Use record Q to write separate equations that balance A and Z, including the emitted beta-minus particle.

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Question 7

What is conserved in the parent-to-daughter transformation shown in record R?

1. The atomic number of the nucleus
2. The number of neutrons in the nucleus
3. The number of protons in the nucleus
4. The mass number of the nucleus

Question 8

A student compares the event in P to a sodium atom becoming Na⁺ by losing an outer electron. Explain how the nuclei differ in these two processes.

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