Endothermic and Exothermic Reactions

What happens in an exothermic reaction?

• Energy is absorbed

• Energy is released

• Temperature decreases

• Reactants gain energy

Which of the following is an example of an exothermic reaction?

• Photosynthesis

• Melting ice

• Burning wood

• Absorbing sunlight

An endothermic reaction occurs when:

• Energy is released into the surroundings

• The reaction produces heat

• Energy is absorbed and stored

• The temperature increases

What type of energy change happens in an exothermic reaction?

• Energy is stored in the products

• Energy is converted from potential to kinetic

• The reactants absorb heat

• The temperature decreases

Which process is an example of an endothermic reaction?

• Freezing water

• Burning fuel

• Boiling water

• Condensation

What is one way to identify an endothermic reaction?

• The products feel colder than the reactants

• The reaction produces light

• The temperature increases

• The reaction releases heat

What kind of reaction occurs in an instant cold pack?

• Exothermic

• Endothermic

• Combustion

• Evaporation

What is a key characteristic of an exothermic reaction?

• It absorbs energy

• The products store more energy than the reactants

• The reaction gives off heat or light

• The products have less kinetic energy than the reactants

Photosynthesis is an example of what type of reaction?

• Exothermic

• Endothermic

• Neutralization

• Combustion

What happens to the atoms in a substance undergoing an exothermic reaction?

• They slow down

• They stop moving

• They gain kinetic energy and move faster

• They absorb energy and remain the same