Year 9 Chemistry Mid-Term Quiz

What is the smallest unit of a chemical element e.g. Carbon?

• Molecule

• Atom

• Compound

• Mixture

In a chemical reaction, the substances that are on the right of the arrow → are called ____.

• Reactants

• Products

• Catalysts

• Enzymes

What are the three main subatomic particles in the structure of an atom?

• protons, neutrons, electrons

• protons, neutrons, ions

• electrons, ions, isotopes

• neutrons, ions, isotopes

In a chemical equation, the substances that undergo a chemical change are called ____.

• Products

• Reactants

• Catalysts

• Isotopes

What are the three types of subatomic particles that make up an atom?

• Protons, Neutrons, Electrons

• Protons, Neutrons, Photons

• Electrons, Photons, Neutrons

• Protons, Photons, Electrons

In the structure of an atom, protons and neutrons are located in the (a)   .

• Orbit

• Nucleus
• Electron cloud

• Shell

What causes electrons to be attracted to protons in the nucleus?

• Magnetic force

• Electrostatic attraction

• Gravitational pull

• Nuclear force

Neutrons in the nucleus have ​ (a)   charge and help stop protons from repelling each other.

• positive
• negative
• variable
• no

What determines the type of atom and the element it belongs to?

• Number of electrons

• Number of protons

• Number of neutrons

• Mass number

The number of protons in an atom is called the ______.

• Mass number

• Atomic number

• Neutron number

• Electron number