CCHEM Unit 12

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. Examples include melting, freezing, and dissolving.

Front

What is a chemical change?

Back

A chemical change is a change that results in the formation of new chemical substances. Examples include burning, rusting, and digestion.

Front

What is a subscript in chemistry?

Back

A subscript is a number written below and to the right of a chemical symbol that indicates the number of atoms of that element in a molecule.

Front

What is a reactant?

Back

A reactant is a substance that undergoes a chemical change in a reaction. It is found on the left side of a chemical equation.

Front

What is a product in a chemical reaction?

Back

A product is a substance that is formed as a result of a chemical reaction. It is found on the right side of a chemical equation.

Front

What is density?

Back

Density is the mass of a substance divided by its volume. It is often expressed in grams per cubic centimeter (g/cm³).

Front

How do you determine the order of liquids by density?

Back

To determine the order of liquids by density, you compare their masses and volumes. The liquid with the highest density will sink, while the one with the lowest density will float.

Front

In a chemical reaction, what does the law of conservation of mass state?

Back

The law of conservation of mass states that mass is neither created nor destroyed in a chemical reaction. The total mass of reactants equals the total mass of products.

Front

What is a coefficient in a chemical equation?

Back

A coefficient is a number placed in front of a chemical formula in a reaction to indicate how many molecules or moles of that substance are involved.

Front

What is the difference between a reactant and a product?

Back

A reactant is a starting material in a chemical reaction, while a product is a substance formed as a result of the reaction.