Question 1

Which of the following best explains why neutrons are essential for the stability of atomic nuclei?

Accepted Answer

Neutrons act as nuclear glue, offsetting the repulsive forces between protons.

Question 2

What is the primary reason that large nuclei, such as uranium, are unstable and prone to radioactive decay?

Accepted Answer

The electric repulsion between protons becomes too strong to be overcome by the nuclear force.

Question 3

Which equation correctly represents the alpha decay of a nucleus with atomic number $Z$ and mass number $A$?

Accepted Answer

$^{A}_{Z}X \rightarrow ^{A-2}_{Z-2}Y + ^{4}_{2}He$

Question 4

Why is iron ($^{56}_{26}Fe$) considered the most stable element in terms of nuclear stability?

Accepted Answer

It has an optimal balance between nuclear attraction and proton repulsion.

Question 5

Which of the following statements about beta decay is correct?

Accepted Answer

Beta decay is the emission of an electron from the nucleus as a neutron converts into a proton.

Question 6

A nucleus with too many protons and not enough neutrons is likely to undergo which type of radioactive decay?

Accepted Answer

Beta-plus decay (positron emission)

Question 7

Which of the following best describes the difference between the nuclear force and electromagnetic force?

Accepted Answer

The nuclear force is short-range and acts between nucleons, while the electromagnetic force is long-range and acts between charged particles.

Question 8

If a nucleus has 20 protons and 20 neutrons, what is its atomic number and mass number?

Accepted Answer

Atomic number: 20, Mass number: 40

Question 9

Which of the following is a consequence of excessive proton repulsion in large nuclei?

Accepted Answer

Radioactive decay, such as alpha decay and nuclear fission

Question 10

What happens to the stability of a nucleus as more neutrons are added, up to a certain point?

Accepted Answer

Stability increases, but after a certain point, adding more neutrons makes the nucleus unstable.

Question 11

Which of the following best describes nuclear fission?

Accepted Answer

The splitting of a heavy nucleus into two smaller nuclei, releasing energy.

Question 12

Which process is responsible for the chain reaction in a nuclear explosion?

Accepted Answer

Nuclear fission, where excess neutrons induce further fission events

Question 13

Why does the nucleus of bismuth ($^{209}_{83}Bi$) eventually break apart?

Accepted Answer

The nuclear force cannot overcome the repulsive force between the large number of protons.

Question 14

Which of the following is NOT a form of radioactive decay discussed in the study materials?

Accepted Answer

Electron capture

Question 15

A gold foil experiment demonstrated the existence of which subatomic particle?

Accepted Answer

Proton

Question 16

Which of the following equations represents beta-minus decay?

Accepted Answer

$^{A}_{Z}X \rightarrow ^{A}_{Z+1}Y + e^{-}$

Question 17

Which statement best describes the role of gamma decay in nuclear processes?

Accepted Answer

Gamma decay releases energy without changing the number of protons or neutrons.

Question 18

Why do alpha and fission decay tend to occur in heavier elements?

Accepted Answer

Excessive proton repulsion in large nuclei makes them unstable, favoring alpha and fission decay.

Question 19

Which of the following best explains why the nucleus does not collapse due to the electric force between protons?

Accepted Answer

The nuclear force is much stronger than the electric repulsion at short distances.

Nuclear Structure, Stability, and Radioactivity

Study Guide - Practice Questions