G9: Subatomic Particles and Chemical Changes Pre-knowledge

Which of the following elements has an atomic number of 6?

• Oxygen

• Carbon

• Nitrogen

• Hydrogen

Which subatomic particle has no charge?

• Proton

• Electron

• Neutron

• Positron

What is the charge of a proton?

• Negative

• Positive

• Neutral

• Variable

What happens during a chemical change?

• The substance retains its original properties.

• The substance changes into a different substance.

• The mass of the substance remains constant.

• The temperature of the substance does not change.

What is the charge of an electron?

• Positive

• Negative

• Neutral

• Zero

What distinguishes a compound from a mixture?

• Compounds are made of two or more different elements chemically bonded.

• Compounds can be separated by physical means.

• Compounds have variable composition.

• Compounds are made of 2 or more atoms, which can be the same or different.

Which of the following is a molecule?

• O

• H₂

• Na

• Cl

Which of the following is a sign of a chemical change?

• Change in state

• Change in shape

• Production of gas

• Dissolving in water

What is the atomic number of an element?

• The number of neutrons in the nucleus.

• The number of protons in the nucleus.

• The total number of electrons.

• The total number of protons and neutrons.

What is the charge of a neutron?

• Positive

• Negative

• Neutral

• Variable