Introduction to Thermal Energy and Systems

Energy stored in chemical bonds only

Potential energy due to object height

Total kinetic motion energy of particles

Energy created by light sources only

Energy is absorbed by the system

Energy moves only within the system

Energy is released into surroundings

Energy stays constant everywhere

Burning a candle flame

Water freezing in a freezer

Hot metal cooling in air

Baking cookies in an oven

The set of reactants before reaction

All matter in the universe

Only the products after reaction

The laboratory room and tools

Endothermic process absorbing energy

Energy moving from surroundings to system

Exothermic process releasing energy

No energy change in the reaction

Faster particles mean warmer matter

Only large particles affect warmth

Particle speed and warmth are unrelated

Slower particles mean warmer matter

Energy was released to surroundings

Energy change cannot be measured

Energy was absorbed from surroundings

Energy moved only within products

Endothermic—energy moves within system only

Exothermic—energy released to surroundings

Endothermic—energy released to surroundings

Exothermic—energy absorbed by system

Energy decreases steadily throughout pathway

Products have more energy than reactants

Reactants and products have equal energy

Products have less energy than reactants

Activation energy is zero

Energy is released to surroundings

Energy is absorbed by the system

No energy change occurs