Atomic and Nuclear Physics
Each subtopic includes About section, revision page link, 10 preview questions, and practice CTAs.
Radioactivity and Half-life
SubtopicRadioactivity and Half-life under Atomic and Nuclear Physics for Grade 9 IB.
Preview questions (no answers)
- 1.
If the count rate of a sample drops from to in , what is the half-life?
A.B.C.D. - 2.
Which particle has the smallest mass?
A.Proton
B.Neutron
C.Alpha particle
D.Electron
- 3.
Why is radioactive waste often stored in lead-lined containers?
A.To keep the waste warm
B.To prevent radiation from escaping into the environment
C.To make the containers easier to carry
D.To speed up the decay process
- 4.
Which radiation type is basically a helium-4 nucleus?
A.Beta minus
B.Beta plus
C.Gamma
D.Alpha
- 5.
Which of the following is true for Beta-plus () decay?
A.The atomic number decreases by 1.
B.The atomic number increases by 1.
C.The mass number decreases by 1.
D.The mass number increases by 1.
- 6.
If an atom's nucleus is represented by , which of the following represents an isotope of ?
A.An atom with the same number of protons but a different mass number.
B.An atom with the same mass number but a different number of protons.
C.An atom with a different number of protons and a different number of electrons.
D.An atom with the same number of neutrons but a different mass number.
- 7.
The total number of nucleons in a nucleus is:
A.131
B.53
C.78
D.184
- 8.
A radioactive sample has an activity of . If the sample size is doubled, what happens to the half-life of the substance?
A.It doubles
B.It is halved
C.It remains the same
D.It increases by a factor of 4
- 9.
Which of the following describes a pair of isotopes?
A.Nuclei with the same mass number but different atomic numbers
B.Nuclei with the same number of neutrons but different number of protons
C.Nuclei with the same atomic number but different mass numbers
D.Nuclei with the same total number of nucleons
- 10.
An isotope has a half-life of 20 minutes. After 1 hour, what is the ratio of the number of decayed nuclei to the number of remaining nuclei?
A.3:1
B.7:1
C.8:1
D.1:7
Download the worksheet for Atomic and Nuclear Physics - Radioactivity and Half-life to practice offline. It includes additional chapter-level practice questions.