Chemical Reactions

A reaction that releases energy in the form of heat is known as . . .

• a synthesis reaction

• an exothermic reaction

• a decomposition reaction

• an endothermic reaction

A reaction that absorbs energy in the form of heat is known as . . .

• a synthesis reaction

• an exothermic reaction

• a decomposition reaction

• an endothermic reaction

the process by which one or more substances change to produce one or more different substances, defines ___________

• conservation of mass

• a chemical reaction

• a chemical formula

• a catalyst

How does this show the conservation of mass?

• The masses of the products are different from the reactants

• matter was destroyed at the end of the chemical reaction

• matter was created at the beginning of the chemical reaction

• the masses of the reactants and products are equal

substance that increases reaction rate by lowering the activation energy of a reaction

• catalyst

• molecule

• endothermic

• synthesis reaction

a change to a substance that happens without forming a new substance

• physical change

• chemical change

• double replacement reaction

• combustion

The total mass of the reactants before a chemical reaction is the same as the total mass of the products after the reaction, because matter cannot be created or destroyed

• Law of Conservation of Mass

• Law of Gravity

• Newton's First Law

• Chemical formula

The number of atoms you begin with in a chemical reaction ...

• must be the same as the number of  atoms you end with
• must be an even number
• can be different to the number you finish with
• changes depending on how much energy is formed

Which one shows that a chemical reaction has occurred?

• dissolving

• melting

• formation of a gas

• bending

One of the signs of a chemical reaction taking place is:

• Bubbles are produced 
• Reactants are not combining
• Products are not forming
• Color is not changing