The concept of half-life applies to: MCQ with Answer and Explanation

The concept of half-life applies to:
A. Only chemical reactions
B. Zero-order reactions only
C. All radioactive decay
D. First-order reactions only
Answer: Option C
Solution (By JKExamLibrary)
Half-life is a characteristic of first-order kinetics, and all radioactive decay follows first-order kinetics. Hence it applies to all radioactive decay processes. Chemical reactions of first order also have constant half-life independent of initial concentration, but radioactive decay is the prime example. Zero-order half-life depends on initial concentration.

Discuss this Question (0)

No comments yet. Be the first to start the discussion!

Practice More chemistry Questions

Question #1
Isobars have different:
A. Both B and C
B. Atomic numbers
C. Mass numbers
D. Numbers of neutrons

Correct Answer: Option A


Explanation:
Isobars are atoms of different elements, so they have different atomic numbers (protons). Since mass number is same, number of neutrons also differs. Example: ⁴⁰Ar (Z=18, N=22) and ⁴⁰Ca (Z=20, N=20). Mass number = 40 same. So both atomic number and neutrons differ. Option D is correct as both B and C are true.

This question belongs to: Science chemistry
Question #2
The acid used in the pickling of metals to remove oxide layers is:
A. Hydrochloric acid
B. Acetic acid
C. Carbonic acid
D. Nitric acid

Correct Answer: Option A


Explanation:
Hydrochloric acid (HCl) is commonly used for pickling (cleaning) steel to remove rust and scale (iron oxides) before further processing like galvanizing or plating. Reaction: Fe₂O₃ + 6HCl → 2FeCl₃ + 3H₂O. Sulfuric acid is also used. Nitric acid is an oxidizer and would passivate some metals. Acetic acid is too weak.

This question belongs to: Science chemistry
Question #3
Which of the following metals is used in the thermite welding process?
A. Zinc
B. Copper
C. Aluminium
D. Lead

Correct Answer: Option C


Explanation:
Thermite: Fe₂O₃ + 2Al → 2Fe + Al₂O₃. Aluminium powder reduces iron oxide, producing molten iron for welding. Al is chosen due to its high reactivity and exothermic reaction.

This question belongs to: Science chemistry