Chemistry -- 8th Grade Science Review

Front

What is a chemical compound?

Back

A chemical compound is a substance formed when two or more elements are chemically bonded together. Examples include water (H2O) and carbon dioxide (CO2).

Front

What is the difference between a chemical change and a physical change?

Back

A chemical change results in the formation of new substances, while a physical change does not change the substance's chemical identity.

Front

What is an example of a chemical change?

Back

An example of a chemical change is the reaction between baking soda and vinegar, which produces carbon dioxide gas.

Front

What evidence indicates a chemical reaction has occurred?

Back

Evidence of a chemical reaction includes the production of gas, formation of a precipitate, change in temperature, and color change.

Front

What is a physical change?

Back

A physical change is a change that affects one or more physical properties of a substance without altering its chemical composition.

Front

What is the formula for sodium bicarbonate?

Back

The formula for sodium bicarbonate is NaHCO3.

Front

What does the term 'precipitate' mean in chemistry?

Back

A precipitate is a solid that forms and settles out of a liquid mixture during a chemical reaction.

Front

What is the significance of the chemical formula in a compound?

Back

The chemical formula indicates the types and numbers of atoms in a compound, providing essential information about its composition.

Front

What is the role of reactants in a chemical reaction?

Back

Reactants are the starting substances that undergo a chemical change to form products.

Front

What is a molecule?

Back

A molecule is a group of two or more atoms bonded together, representing the smallest fundamental unit of a chemical compound.