7ALP - Understanding Physical and Chemical Changes (level 9)

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

• Melting of ice

• Colour change

• Breaking a glass

• Dissolving sugar in water

What is produced during a chemical reaction that indicates a gas is being formed?

• A solid precipitate

• A temperature decrease

• Bubbles

• A colour change

Which of the following is a physical change?

• Rusting of iron

• Burning of wood

• Boiling of water

• Baking a cake

What discovery led to the change in the model of the atom?

• Discovery of molecules

• Discovery of electrons, protons, and neutrons

• Discovery of isotopes

• Discovery of chemical bonds

Which of the following is a result of natural radioactive decay?

• Formation of new molecules

• Change from stable to unstable atoms

• Change from unstable to stable atoms

• Increase in atomic mass

Which gas is commonly tested using a glowing splint?

• Carbon dioxide

• Oxygen

• Hydrogen

• Nitrogen

What is the main indicator of a precipitate forming in a chemical reaction?

• A change in temperature

• A solid forming in a solution

• A change in colour

• Production of a gas

Which of the following changes involves a temperature change as a sign of a chemical reaction?

• Freezing water

• Dissolving salt in water

• Combustion of wood

• Melting butter

What is the charge of a neutron?

• Positive

• Negative

• Neutral

• Variable

Which of the following is NOT a sign of a chemical change?

• Formation of a precipitate

• Change in state

• Production of gas

• Temperature change