Who first proposed the idea that all matter is made up of indivisible particles called 'atomos'?

• J.J. Thomson

• Ernest Rutherford

• Democritus

• John Dalton

What did J.J. Thomson discover in the late 1800s?

• The neutron

• The nucleus

• The proton

• The electron

What model did J.J. Thomson propose?

• Plum pudding model

• Planetary model

• Nuclear model

• Quantum model

What did Ernest Rutherford's gold foil experiment reveal?

• Atoms are solid

• Electrons are in fixed orbits

• Atoms are mostly empty space

• Atoms have no nucleus

In Niels Bohr's model, how do electrons move around the nucleus?

• Randomly

• In pairs

• In a cloud

• In fixed orbits

What does the atomic number represent?

• Number of electrons

• Number of neutrons

• Total number of particles

• Number of protons

Which particles contribute to the atomic mass?

• Protons and neutrons

• Only protons

• Electrons

• Only neutrons

How many electrons can the first shell hold?

• 2

• 8

• 18

• 32

What are valence electrons?

• Electrons that are lost

• Electrons in the nucleus

• Electrons that are gained

• Electrons available for bonding

Which group of elements is known as alkali metals?

• Group 18

• Group 13

• Group 2

• Group 1