CHEMISTRY: CHEMICAL REACTIONS AND EQUATIONS

Reactants

________ absorb energy as they become products, hence the products have more potential energy than the reactions.

+ sign

A(n) ________ is used to separate each of the reactants and each of the products.

Exothermic

________: processes that release thermal energy when they occur.

exothermic reactions

In ________, the products have less potential than the reactants.

Physical change

change in appearance of the starting material

Chemical change

change of properties between the product and reactants

Endothermic

processes that require energy in order to occur

Endothermic changes include

The physical change of ice melting, food cooking, and evaporating liquid water

Exothermic

processes that release thermal energy when they occur

Examples include

the burning of carbon in oxygen and freezing of water

Balanced Chemical Equation

C + O₂ → CO₂

Unbalanced Chemical Equation

H₂ + O₂  → H₂O

law of conservation of mass

states that matter is neither created nor destroyed in chemical reactions.

product

substance that is produced by a chemical reaction

reactant

substance that enters into a chemical reaction