Post Utme Physics Past Questions and Answers

Question 1031:

The count rate of an alpha-particle source is 400 per minute.
If the half-life of the source is 5 days, what would be the count rate per minute after 15 days?

A. 20
B. 25
C. 5
D. 200
E. 400

Question 1032:

The nucleon number and the proton numbers of a neutral atom of an element are 238 and 92 respectively.
What is the number of neutron in the atom?

A. 330
B. 238
C. 146
D. 119
E. 73

Question 1033:

In 24 days a radioactive isotope decreases in mass from \(64 g\) to \(2 g\).
what is the half life of the radioactive material?

A. \(0.75\) days
B. \(2.58\) days
C. \(4.00\) days
D. \(4.80\) days
E. \(6.00\) days

Question 1034:

When an atom gains or loses a charge,
it becomes ____________

A. An ion
B. An electron
C. A neutron
D. A proton
E. A deuteron

Question 1035:

Beta particles are ____________

A. Electrons
B. Protons
C. Neutrons
D. Helium nuclei
E. Tritium, nuclei