Unit 2: Structure of Atoms

MCQs on the Structure of Atoms

1. What is the charge of an electron?
   • A) Positive
   • B) Negative
   • C) Neutral
   • D) Zero
   • Answer: B) Negative
2. Who is credited with the discovery of the electron?
   • A) Ernest Rutherford
   • B) Niels Bohr
   • C) J.J. Thomson
   • D) James Chadwick
   • Answer: C) J.J. Thomson
3. In which part of the atom are protons located?
   • A) Electron cloud
   • B) Nucleus
   • C) Neutron shell
   • D) Orbital
   • Answer: B) Nucleus
4. What is the relative charge of a neutron?
   • A) +1
   • B) -1
   • C) 0
   • D) -2
   • Answer: C) 0
5. The atomic number of an element is equal to the number of:
   • A) Neutrons
   • B) Electrons
   • C) Protons
   • D) Neutrons + Protons
   • Answer: C) Protons
6. Which scientist proposed the planetary model of the atom?
   • A) J.J. Thomson
   • B) Niels Bohr
   • C) Ernest Rutherford
   • D) John Dalton
   • Answer: B) Niels Bohr
7. What does the mass number of an atom represent?
   • A) Number of protons
   • B) Number of electrons
   • C) Number of protons and neutrons
   • D) Number of neutrons and electrons
   • Answer: C) Number of protons and neutrons
8. Which subatomic particle has a mass of approximately 1 atomic mass unit (amu)?
   • A) Electron
   • B) Proton
   • C) Neutron
   • D) Both B and C
   • Answer: D) Both B and C
9. What is the charge of a proton?
   • A) Positive
   • B) Negative
   • C) Neutral
   • D) Zero
   • Answer: A) Positive
10. Which atomic model is also known as the “plum pudding model”?
    • A) Bohr Model
    • B) Rutherford Model
    • C) Thomson Model
    • D) Quantum Model
    • Answer: C) Thomson Model