Y8 Chemistry Unit Review

A chemical change can alter a substance by:

• changing its physical state without altering its chemical composition.

• rearranging its atoms to form a new substance with different properties.

• dissolving it in water to form a solution.

• breaking it into smaller pieces without changing its chemical identity.

State the different ways a chemical change can be detected.

• Change in color, temperature, formation of a precipitate, and gas production

• Only change in color

• Only change in temperature

• Only formation of a precipitate

A chemical reaction is a process that involves the transformation of one or more substances into different substances. What is a chemical reaction?

• A process that involves the transformation of one or more substances into different substances

• A process that involves the transformation of energy into matter

• A process that involves the transformation of matter into energy

• A process that involves the transformation of substances into energy

Identify reactants and products in a chemical reaction.

• Reactants are substances that start a chemical reaction, and products are substances that are produced in the reaction.

• Reactants are substances that are produced in the reaction, and products are substances that start a chemical reaction.

• Reactants and products are the same in a chemical reaction.

• Reactants and products cannot be identified in a chemical reaction.

Write a word reaction for a chemical change.

• A + B -> AB

• AB -> A + B

• A + B <-> AB

• A + B -> A + B

Define the term 'Irreversible'.

• Irreversible means something that cannot be undone or altered.

• Irreversible means something that can be easily changed.

• Irreversible refers to a temporary state.

• Irreversible is a term used for reversible processes.

Define the term 'Chemical reactions'.

• A process that involves rearrangement of the molecular or ionic structure of a substance.

• A type of physical change that alters the form of a substance without changing its identity.

• A method of separating mixtures based on differences in their volatilities.

• A technique used to determine the age of an artifact.

Define the term 'Fuel'.

• A substance that is used to provide heat or power, usually by being burned.

• A type of food that is consumed for energy.

• A chemical element that is used in the production of plastics.

• A liquid used for cleaning purposes.

Define the term 'Combustion'.

• The process of burning something.

• The process of freezing something.

• The process of melting something.

• The process of evaporating something.

Which of the following is a characteristic of a physical change?

• A) New substances are formed

• B) Often easy to reverse

• C) Bonds between particles change

• D) All of the above