Signs of chemical reactions

Front

What is used to represent the number of each atom in a molecule?

Back

The subscript.

Front

What is a balanced chemical equation?

Back

A chemical equation where the number of atoms for each element is the same on both sides of the equation.

Front

What type of reaction absorbs heat from the surroundings?

Back

Endothermic reaction.

Front

What is an exothermic reaction?

Back

A chemical reaction that releases heat to the surroundings.

Front

What evidence indicates that a new substance has formed during a chemical reaction?

Back

A new substance has formed.

Front

What happens to the temperature in an endothermic reaction?

Back

The temperature decreases.

Front

What is a precipitate?

Back

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

Front

What does it mean if a solid dissolves in a liquid?

Back

It may not indicate a chemical reaction; it could be a physical change.

Front

What is the significance of coefficients in a chemical equation?

Back

Coefficients indicate the number of molecules or moles of a substance involved in the reaction.

Front

What is the law of conservation of mass?

Back

Mass is neither created nor destroyed in a chemical reaction.