Radioactive Decay Stable and Unstable Nuclei

What subatomic particles are found in the nucleus of an atom?

• Protons and electrons

• Neutrons and electrons

• Protons and neutrons

• Protons, neutrons, and electrons

What condition can lead to an unstable nucleus?

• Too many electrons

• Too few protons

• An imbalance of protons or neutrons

• A strong nuclear force

What happens to the mass number and atomic number of an atom during alpha decay?

• Mass number decreases by 2, atomic number decreases by 4

• Mass number decreases by 4, atomic number decreases by 2

• Mass number stays the same, atomic number increases by 1

• Mass number stays the same, atomic number decreases by 1

In beta-minus decay, what transformation occurs within the nucleus?

• A proton changes into a neutron and a positron.

• A neutron changes into a proton and an electron.

• Two protons and two neutrons are emitted.

• An electron is captured by a proton.