Structure of the Atom
Each subtopic includes About section, revision page link, 10 preview questions, and practice CTAs.
Charged Particles in Matter
SubtopicCharged Particles in Matter under Structure of the Atom for Grade 9 CBSE.
Preview questions (no answers)
- 1.
What is the relative mass of an electron?
A.1 unit
B.1/2000 unit
C.2000 units
D.0.5 unit
- 2.
Which scientist proposed that electrons are embedded in a positive sphere?
A.Rutherford
B.Goldstein
C.Thomson
D.Dalton
- 3.
Which subatomic particle is about 2000 times heavier than an electron?
A.Neutron
B.Alpha particle
C.Proton
D.Hydrogen nucleus
Download the worksheet for Structure of the Atom - Charged Particles in Matter to practice offline. It includes additional chapter-level practice questions.
Thomson’s and Rutherford’s Model
SubtopicThomson’s and Rutherford’s Model under Structure of the Atom for Grade 9 CBSE.
Preview questions (no answers)
- 1.
In Rutherford's experiment, the foil used was made of gold primarily because it is highly:
A.Ductile
B.Malleable
C.Reactive
D.Conductive
- 2.
The existence of a heavy, positively charged center in an atom was proven by:
A.Dalton's theory
B.Rutherford's scattering experiment
C.Thomson's discharge tube
D.Bohr's model
- 3.
Thomson's model compared the atom to which of the following desserts?
A.Ice cream
B.Chocolate cake
C.Christmas pudding
D.Apple pie
Download the worksheet for Structure of the Atom - Thomson’s and Rutherford’s Model to practice offline. It includes additional chapter-level practice questions.
Bohr’s Model of Atom
SubtopicBohr’s Model of Atom under Structure of the Atom for Grade 9 CBSE.
Preview questions (no answers)
- 1.
Which of the following can be concluded from Bohr’s model regarding the stability of atoms?
A.Electrons will eventually fall into the nucleus
B.Atoms are unstable because electrons radiate energy
C.Electrons do not lose energy while in discrete orbits, making atoms stable
D.Stability depends only on the number of neutrons
- 2.
Which shell is represented by ?
A.K shell
B.L shell
C.M shell
D.N shell
- 3.
In the Bohr-Bury scheme, electrons are not accommodated in a given shell unless __________.
A.The nucleus is stable
B.The inner shells are filled
C.The outer shells are filled
D.The atom is ionized
Download the worksheet for Structure of the Atom - Bohr’s Model of Atom to practice offline. It includes additional chapter-level practice questions.
Preview questions (no answers)
- 1.
Boron-10 and Boron-11 are isotopes. How do they differ?
A.Boron-11 has one more proton
B.Boron-11 has one more electron
C.Boron-11 has one more neutron
D.Boron-11 has one fewer neutron
- 2.
Which of the following atoms has 6 neutrons and 5 protons?
A.Carbon-11
B.Boron-11
C.Nitrogen-11
D.Carbon-12
- 3.
If you subtract the number of protons from the mass number, you get the number of:
A.Electrons
B.Orbits
C.Neutrons
D.Valency
Download the worksheet for Structure of the Atom - Neutrons to practice offline. It includes additional chapter-level practice questions.
Preview questions (no answers)
- 1.
What is the valency of an element with 17 protons?
A.7
B.1
C.17
D.0
- 2.
An atom with 8 valence electrons is said to have a/an:
A.Incomplete shell
B.Octet
C.Duplet
D.Valency of 8
- 3.
Which element has 3 valence electrons?
A.Carbon
B.Boron
C.Beryllium
D.Lithium
Download the worksheet for Structure of the Atom - Valency to practice offline. It includes additional chapter-level practice questions.
Atomic Number and Mass Number
SubtopicAtomic Number and Mass Number under Structure of the Atom for Grade 9 CBSE.
Preview questions (no answers)
- 1.
What is the mass number of an atom containing 1 proton and 0 neutrons?
A.0
B.1
C.2
D.3
- 2.
If an atom has 14 protons, it is an atom of:
A.Aluminium
B.Silicon
C.Carbon
D.Phosphorus
- 3.
The total number of protons in the nucleus is known as the:
A.Mass number
B.Atomic number
C.Neutron number
D.Nucleon number
Download the worksheet for Structure of the Atom - Atomic Number and Mass Number to practice offline. It includes additional chapter-level practice questions.
Isotopes and Isobars
SubtopicIsotopes and Isobars under Structure of the Atom for Grade 9 CBSE.
Preview questions (no answers)
- 1.
Which isotope of carbon is most abundant in nature?
A.Carbon-12
B.Carbon-13
C.Carbon-14
D.Carbon-11
- 2.
In which isotope is the number of neutrons equal to the number of protons?
A.B.C.D. - 3.
Why do isobars have different chemical properties?
A.They have the same number of protons
B.They have different atomic numbers
C.They have the same mass number
D.They have the same number of neutrons
Download the worksheet for Structure of the Atom - Isotopes and Isobars to practice offline. It includes additional chapter-level practice questions.