Class 9 Practice Level 1 - Structure of the Atom

Total questions: 40

What is the smallest unit of an element that retains the properties of that element?

Topic: Basic Atomic Structure

Molecule

Atom

Electron

Proton

None

Who discovered the electron?

Topic: Discovery of Electrons

J.J. Thomson

Ernest Rutherford

Niels Bohr

James Chadwick

None

What is the center of an atom called?

Topic: Atomic Nucleus

Electron cloud

Proton zone

Neutron area

Nucleus

None

Which subatomic particle has a positive charge?

Topic: Subatomic Particles

Electron

Neutron

Proton

Positron

None

Who is credited with the discovery of the atomic nucleus?

Topic: Discovery of Nucleus

J.J. Thomson

Ernest Rutherford

Niels Bohr

James Chadwick

None

Which particles contribute most to the atomic mass of an atom?

Topic: Atomic Mass Calculation

Electrons and protons

Electrons and neutrons

Protons and neutrons

Only protons

None

How many electrons can the first shell of an atom hold?

Topic: Electron Configuration

None

The atomic number of an element is determined by the number of which particles?

Topic: Atomic Number

Electrons

Neutrons

Protons

Neutrons and protons

None

What are atoms of the same element with different numbers of neutrons called?

Topic: Isotopes

Isomers

Isobars

Isotopes

Isoelectronic

None

10.

What is the charge of an electron?

Topic: Electron Charge

Positive

Negative

Neutral

Variable

None

11.

Who discovered the neutron?

Topic: Neutron Discovery

J.J. Thomson

Ernest Rutherford

Niels Bohr

James Chadwick

None

12.

Who proposed the plum pudding model of the atom?

Topic: Atomic Models

Ernest Rutherford

J.J. Thomson

Niels Bohr

John Dalton

None

13.

According to Bohr's model, electrons move in fixed orbits around the nucleus called:

Topic: Bohr’s Model

Orbitals

Shells

Clouds

Nodes

None

14.

What is the approximate mass of a proton or neutron in atomic mass units (amu)?

Topic: Atomic Mass Unit (amu)

0.0005 amu

1 amu

2 amu

10 amu

None

15.

In Rutherford's gold foil experiment, most alpha particles passed through the foil because:

Topic: Rutherford’s Experiment

Atoms are mostly empty space.

The gold foil was very thin.

Alpha particles are very small.

Alpha particles are very fast.

None

16.

Electrons in the outermost shell of an atom are called:

Topic: Valence Electrons

Core electrons

Inner electrons

Valence electrons

Shell electrons

None

17.

The atomic mass of an element is calculated by summing the number of:

Topic: Atomic Mass Calculation

Protons and electrons

Neutrons and electrons

Protons and neutrons

Protons, neutrons, and electrons

None

18.

Atoms with the same mass number but different atomic numbers are called:

Topic: Isobars

Isotopes

Isobars

Isomers

Isotones

None

19.

What is the chemical symbol for carbon?

Topic: Atomic Symbol

None

20.

Which part of the atom contains most of its mass?

Topic: Atomic Structure

Electron cloud

Nucleus

Valence shell

First shell

None

21.

What experiment led to the discovery of the electron?

Topic: Electron Discovery

Gold foil experiment

Oil drop experiment

Cathode ray experiment

Rutherford's scattering experiment

None

22.

Who is known as the father of modern atomic theory?

Topic: Atomic Theory

Niels Bohr

John Dalton

J.J. Thomson

Ernest Rutherford

None

23.

What is the charge of a neutron?

Topic: Neutron Charge

Positive

Negative

Neutral

Variable

None

24.

In Bohr's model, what determines the energy level of an electron?

Topic: Bohr’s Model

The speed of the electron

The distance from the nucleus

The number of protons

The number of neutrons

None

25.

Who is credited with discovering the proton?

Topic: Proton Discovery

J.J. Thomson

Ernest Rutherford

Niels Bohr

James Chadwick

None

26.

Which model of the atom is also known as the planetary model?

Topic: Atomic Models

Thomson's model

Rutherford's model

Bohr's model

Dalton's model

None

27.

Compared to protons and neutrons, the mass of an electron is:

Topic: Electron Mass

Much larger

Slightly larger

Much smaller

Almost the same

None

28.

The number of protons in an atom is also known as its:

Topic: Atomic Number

Atomic mass

Atomic number

Mass number

Isotopic number

None

29.

The nucleus of an atom contains:

Topic: Nucleus Composition

Only protons

Only neutrons

Protons and neutrons

Protons, neutrons, and electrons

None

30.

The outermost shell of an atom is called the:

Topic: Valence Shell

Inner shell

Core shell

Valence shell

Orbital shell

None

31.

The standard unit for measuring atomic mass is:

Topic: Atomic Mass Unit

Gram

Mole

Atomic mass unit (amu)

Dalton

None

32.

What is the chemical symbol for hydrogen?

Topic: Chemical Symbols

None

33.

How many electrons can the second shell of an atom hold?

Topic: Electron Configuration

None

34.

The mass of a neutron is approximately:

Topic: Neutron Mass

Equal to the mass of an electron

Half the mass of a proton

Equal to the mass of a proton

Twice the mass of a proton

None

35.

Which part of the atom is mostly empty space?

Topic: Atomic Structure

Nucleus

Electron cloud

Proton zone

Neutron area

None

36.

The identity of an element is determined by its number of:

Topic: Element Identity

Neutrons

Electrons

Protons

Isotopes

None

37.

The third shell of an atom can hold a maximum of:

Topic: Shell Capacity

8 electrons

18 electrons

32 electrons

2 electrons

None

38.

What is the charge of a proton?

Topic: Proton Charge

Positive

Negative

Neutral

Variable

None

39.

Which scientist proposed that electrons orbit the nucleus in specific energy levels?

Topic: Atomic Models

J.J. Thomson

Ernest Rutherford

Niels Bohr

James Chadwick

None

40.

What is the chemical symbol for oxygen?

Topic: Element Symbols

None

1 out of 40

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Class 9 Practice Level 1 - Structure of the Atom

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