Journey Inside the Atom — Class 9 Science NCERT Solutions (Free)
Free step-by-step NCERT solutions for Class 9 Science chapter "Journey Inside the Atom" — 8 important questions with detailed answers for CBSE board exam preparation.
TL;DR: Free step-by-step NCERT solutions for Class 9 Science chapter "Journey Inside the Atom" — 8 important questions with detailed answers for CBSE board e…
By Syllab.in · Updated
Key Questions Covered:
- What are the three subatomic particles and their charges?
- State and explain Thomson's model of atom.
- What are the main features of Rutherford's model of atom?
- + 5 more questions in the full chapter
Solutions Summary:
| Question | Status |
|---|---|
| What are the three subatomic particles and their charges? | ✓ Solved |
| State and explain Thomson's model of atom. | ✓ Solved |
| What are the main features of Rutherford's model of atom? | ✓ Solved |
Showing 3 of 8 questions
Q1: What are the three subatomic particles and their charges?
The three subatomic particles are:
(1) Electron — negatively charged (charge = -1), mass = 1/1836 amu, found in orbitals around nucleus
(2) Proton — positively charged (charge = +1), mass = 1 amu, present in nucleus
(3) Neutron — neutral (charge = 0), mass ≈ 1 amu, present in nucleus
Q2: State and explain Thomson's model of atom.
Thomson's model (plum pudding model):
Atom is a sphere of positive charge with electrons embedded in it like raisins in a pudding.
Characteristics: (1) Positive charge uniformly distributed throughout atom
(2) Electrons scattered throughout in this positive charge
(3) Atom is electrically neutral
Li...
Q3: What are the main features of Rutherford's model of atom?
Rutherford's nuclear model:
(1) Atom has a small, dense, positively charged nucleus at center
(2) Electrons revolve around nucleus in circular paths
(3) Most of atom's mass is concentrated in nucleus
(4) Nucleus contains protons; electrons in orbits
(5) Atom is mostly empty space
Limitation: Could n...
Showing 3 of 8 questions. Visit the full page for complete solutions.