Chemical Reactions

Which statement best describes what occurs during a chemical reaction?

• The bonds in reactants break so that elements can rearrange and form new products

• The bonds in products break so that elements can rearrange and form new reactants.

• Reactant atoms are destroyed, releasing energy which is used to create new product atoms.

• Bonds within the nucleus of reactant atoms are broken and rearranged to form new product atoms

The substances involved in a chemical reaction may be elements or compounds.

• True

• False

During a chemical reaction

• chemical bonds break.

• matter is destroyed.

• new atoms form.

• a gas is always produced

What is an endothermic reaction?

• A reaction where energy is absorbed, cooling the reactants

• A reaction where energy is released, heating the reactants.

• A reaction where one of the elements is destroyed in the process

• A reaction that always creates a gas.

In addition to reactants, all chemical reactions require _____ in order for the reaction to occur.

Which statement(s) is/are TRUE for all chemical reactions?

• There is an overall energy release during all chemical reactions.

• Energy is released when bonds are formed.

• Energy is absorbed when bonds are broken.

• Reactant elements and/or compounds rearrange to form chemically new products.

The substances that start a chemical reaction are called _____.

The substances produced in a chemical reaction are called _____.

What is an exothermic reaction?

• A reaction where energy is absorbed, cooling the reactants

• A reaction where energy is released, heating the reactants.

• A reaction where one of the elements is destroyed in the process

• A reaction that always creates a gas.

A chemical bon involving the sharing of electrons between two or more elements is called a ______________

• Covalent bond

• Ionic bond

• Hydrogen bond

• Weak bond