An atom of element X has 6 protons and 8 neutrons. Its mass number is: MCQ with Answer and Explanation

An atom of element X has 6 protons and 8 neutrons. Its mass number is:
A. 2
B. 8
C. 14
D. 6
Answer: Option C
Solution (By JKSSB Mock Tests)
Mass number = protons + neutrons = 6 + 8 = 14. This corresponds to carbon-14 isotope. Atomic number = 6 (carbon).

Discuss this Question (0)

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

Practice More chemistry Questions

Question #1
Gamma rays have no charge and no mass. They are:
A. Electromagnetic radiation
B. Electrons
C. Helium nuclei
D. Particles

Correct Answer: Option A


Explanation:
Gamma rays are high-frequency electromagnetic waves emitted from the nucleus. They have very high penetration power and are used in cancer therapy.

This question belongs to: Science chemistry
Question #2
A gas at 300 K occupies 2 L. If the temperature is raised to 600 K at constant pressure, the volume becomes:
A. 2 L
B. 1 L
C. 4 L
D. 6 L

Correct Answer: Option C


Explanation:
Charles' law: V₁/T₁ = V₂/T₂. V₂ = V₁ × T₂/T₁ = 2 L × 600 K / 300 K = 4 L. Volume doubles as absolute temperature doubles. Note: must use Kelvin, not Celsius. (600 K = 327°C). If mass and pressure are constant, volume is directly proportional to absolute temperature.

This question belongs to: Science chemistry
Question #3
Which of the following is a radioactive isotope used in the treatment of cancer?
A. Cobalt-60
B. Carbon-12
C. Sodium-23
D. Phosphorus-31

Correct Answer: Option A


Explanation:
Cobalt-60 emits gamma rays used in radiotherapy to destroy cancerous cells. Carbon-12 and sodium-23 are stable. Phosphorus-32 is radioactive but used as tracer, not for cancer therapy.

This question belongs to: Science chemistry