Post Utme Physics Past Questions and Answers

Question 721:

The electrochemical equivalent of platinum is 5.0x 0-7kgC^-1 To place put 1.0kg of platinum, a current of 100A must be passed through an appropriate vessel for ____________

A. 5.6 hours
B. 56 hours
C. 1.4 x 10⁴ hours
D. 2.0 x10⁴ hours

Question 722:

Which of the following statements are TRUEUE of isotopes?
I. isotopes of an element have the same chemical properties because they have the same chemical properties because they have the same number of electrons.
II. Isotopes of elements are normally separated using [physical properties
III. Isotopes of an elements have the same number of protons in their nuclei

A. I and II only
B. I and III only
C. II and III
D. I II and III

Question 723:

When an atom loss or gains a charge it becomes ____________

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

Question 724:

4g of radioactive radiation half-life 10 days is spilled on a laboratory flood.
How long would it take to disintegrate 3.5g of materials

A. 11/14 days
B. 83/4 days
C. 30 days
D. 80 days

Question 725:

Which of the following are TRUE for decay
I. mass number decreases by four
II. Atomic number decreases by too
III. mass number does not change

A. I and II only
B. II and only
C. And II only
D. I, II and III