Chapter-12 Atomic Structure — Online MCQ Test
SCIENCE · Samacheer Kalvi 8th · Tamil Nadu State Board
Practice Chapter-12 Atomic Structure with a free chapter-wise online MCQ test.
This chapter covers: atom electron proton Covers atoms molecules subatomic particles and atomic models.
AI-generated questions from basic to board-exam level, with instant results and explanations.
Chapter-12 Atomic Structure — Important Questions & Answers
What is the center of an atom called?
- A. Electron cloud
- B. Nucleus
- C. Orbit
- D. Molecule
Answer: B. Nucleus
The nucleus is the dense central part of an atom. It contains protons and neutrons.
The nucleus is the dense central part of an atom. It contains protons and neutrons.
Which subatomic particle has a negative charge?
- A. Proton
- B. Neutron
- C. Electron
- D. Nucleus
Answer: C. Electron
Electrons carry negative charge and revolve around the nucleus in an atom.
Electrons carry negative charge and revolve around the nucleus in an atom.
Which statement best describes a molecule?
- A. A single particle with only protons
- B. A group of two or more atoms chemically combined
- C. The center of an atom
- D. A particle with negative charge
Answer: B. A group of two or more atoms chemically combined
A molecule is formed when two or more atoms join together by chemical bonds.
A molecule is formed when two or more atoms join together by chemical bonds.
A student says atoms are indivisible and cannot be broken into smaller particles. Which discovery proves this statement wrong?
- A. Discovery of cells
- B. Discovery of subatomic particles
- C. Discovery of rocks
- D. Discovery of plants
Answer: B. Discovery of subatomic particles
The discovery of electrons, protons, and neutrons showed that atoms have smaller parts inside them.
The discovery of electrons, protons, and neutrons showed that atoms have smaller parts inside them.
Which is the best conclusion when an atom gains one electron?
- A. It becomes a positively charged ion
- B. It becomes a negatively charged ion
- C. It becomes a molecule
- D. It becomes a neutral atom with more protons
Answer: B. It becomes a negatively charged ion
Gaining an electron gives the atom extra negative charge, so it becomes a negatively charged ion.
Gaining an electron gives the atom extra negative charge, so it becomes a negatively charged ion.