Chapter 3: Classification of Elements and Periodicity in Properties — Online MCQ Test
CHEMISTRY · CLASS 11 FIRST PUC · Karnataka State Board
Practice Chapter 3: Classification of Elements and Periodicity in Properties with a free chapter-wise online MCQ test.
This chapter covers: Periodic table Periodic law Atomic radius Ionization enthalpy Electron affinity Electronegativity Metallic character Non metallic character Periodic trends.
AI-generated questions from basic to board-exam level, with instant results and explanations.
Chapter 3: Classification of Elements and Periodicity in Properties — Important Questions & Answers
According to the modern periodic law, the properties of elements are periodic functions of their ____.
- A. atomic masses
- B. atomic numbers
- C. neutron numbers
- D. valence electrons only
Answer: B. atomic numbers
Modern periodic law states that the physical and chemical properties of elements are periodic functions of their atomic numbers.
Modern periodic law states that the physical and chemical properties of elements are periodic functions of their atomic numbers.
Which of the following is a period in the periodic table?
- A. A vertical column
- B. A horizontal row
- C. A family of elements with same valency
- D. A group of transition metals only
Answer: B. A horizontal row
A period is a horizontal row in the periodic table.
A period is a horizontal row in the periodic table.
Across a period, the metallic character generally:
- A. increases
- B. decreases
- C. remains unchanged
- D. first increases then remains constant
Answer: B. decreases
Metallic character decreases across a period as atoms become less likely to lose electrons.
Metallic character decreases across a period as atoms become less likely to lose electrons.
Which element is expected to have the lowest first ionization enthalpy?
- A. Be
- B. B
- C. C
- D. N
Answer: B. B
Boron has a lower first ionization enthalpy than beryllium because its electron is removed from a higher-energy 2p orbital.
Boron has a lower first ionization enthalpy than beryllium because its electron is removed from a higher-energy 2p orbital.
A student says: 'Fluorine should have a greater electron affinity than chlorine because fluorine is more electronegative.' Which is the best response?
- A. The statement is correct; electron affinity always follows electronegativity exactly
- B. The statement is incorrect; chlorine has slightly higher electron affinity than fluorine due to less electron-electron repulsion in a larger 3p orbital
- C. The statement is incorrect; fluorine cannot gain electrons
- D. The statement is correct only in periods, not groups
Answer: B. The statement is incorrect; chlorine has slightly higher electron affinity than fluorine due to less electron-electron repulsion in a larger 3p orbital
Electron affinity and electronegativity are related but not identical. Fluorine's small size increases repulsion when an extra electron is added, so chlorine has slightly higher electron affinity.
Electron affinity and electronegativity are related but not identical. Fluorine's small size increases repulsion when an extra electron is added, so chlorine has slightly higher electron affinity.