The atomic number of an element is determined by the number of: MCQ with Answer and Explanation

The atomic number of an element is determined by the number of:
A. Nucleons
B. Neutrons
C. Protons
D. Electrons
Answer: Option C
Solution (By JKExamLibrary)
Atomic number (Z) is the number of protons in the nucleus, which defines the identity of the element. In a neutral atom, the number of electrons equals Z. Neutrons contribute to mass number but not atomic number. Isotopes have same Z but different number of neutrons. Nucleons are total protons + neutrons = mass number. The modern periodic table is based on atomic number.

Discuss this Question (0)

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

Practice More chemistry Questions

Question #1
The process of vulcanization of rubber was invented by:
A. Leo Baekeland
B. Wallace Carothers
C. Charles Goodyear
D. Hermann Staudinger

Correct Answer: Option C


Explanation:
Vulcanization is the chemical process of converting natural rubber or related polymers into more durable materials by adding sulfur or other equivalent curatives. This process was discovered by Charles Goodyear in 1839, revolutionizing the rubber industry by making it less sticky and more temperature-resistant.

This question belongs to: Science chemistry
Question #2
Which of the following metals is used in the thermite welding process?
A. Zinc
B. Aluminium
C. Lead
D. Copper

Correct Answer: Option B


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
Question #3
According to Fajan's rules, which of the following conditions favors the formation of a covalent bond?
A. Large cation and small anion
B. Small cation and small anion
C. Small cation and large anion
D. Large cation and large anion

Correct Answer: Option C


Explanation:
Fajan's rules state that covalent character in an ionic bond increases with greater polarizing power of the cation and greater polarizability of the anion. A small cation has high charge density (high polarizing power), and a large anion has loosely held outer electrons (high polarizability), favoring covalency.

This question belongs to: Science chemistry