Energy Changes in Chemistry

Kinetic Energy: Energy due to the position and motion of an object.
Potential Energy: Stored energy based on position.
Electrical Energy: Energy due to electric charge movements.
Light Energy: Energy that is visible and can be utilized in processes like photosynthesis.
Mechanical Energy: Sum of potential and kinetic energy in a mechanical system.

Energy cannot be created or destroyed; it can only change from one form to another.
Total energy remains constant in an isolated system, emphasizing the transformations that occur in daily life.

Chemical Reaction: A process that involves rearranging the atoms of substances to create new substances.
- Energy Involvement: Reactions can either absorb or release energy.
- Example of Energy Sources in Reactions:
- Photosynthesis: Light energy is transformed into chemical energy.
- Burning Fossil Fuels: Chemical energy is converted into heat and light energy.
- Nuclear Reactions: Significant energy is released from nuclear fission or fusion.

Fireworks: Release light and sound energy upon combustion.
Electric Motor: Converts electrical energy into kinetic energy for motion.
Hair Dryer: Converts electrical energy into thermal energy (heat).
Battery: Changes stored chemical energy into electrical energy to power devices.
Automobile Engine: Converts chemical energy from fuel into mechanical energy to move the vehicle.
Solar Cell: Converts light energy directly into electrical energy.

All chemical reactions involve an energy change, either gaining or losing energy.
Common examples include evaporation (gain of energy) and condensation (loss of energy) seen in daily life, such as water droplets forming when humid air cools down.
Sublimation observed with substances like dry ice shows direct transition from solid to gas, illustrating energy changes in phase transitions.

Energy plays a critical role in both physical processes and chemical reactions, with various forms of energy interacting throughout the processes observed in everyday life.