Energy and Changes in Material Systems

Review Material System – Any kind of matter whose limits are undefined due to its nature or to its size

Review Body – Matter with defined limits

The Concept of Change A change is any transformation that can be measured Material systems and bodies change Everything (alive or not) changes. Things change when they interact with another material system, body or with itself

The Concept of Change In any change, energy is exhanged between a material system (or a body) and its surroundings Material System or Body Surroundings

Classifying Material Systems 1.Open Systems Exchange Matter and Energy with their Surroundings Exchanges matter with its surroundings when the water evaporates, and energy when the coffee cools

Classifying Material Systems 2. Closed Systems Only exchange energy with their surroundings The system can not exchange matter with its surroundings (enclosed by plastic) but it can exchange energy as water gets colder with time.

Classifying Material Systems 3. Isolated Systems Cannot exchange energy or matter with their surroundings The water inside the thermos maintains the same level of matter and mass and the energy doesn’t change (in an ideal system)

Classifying Material Systems Energy is present in all material systems that exist within the universe! However, it is also present in waves which can transfer energy without transporting matter.

Types of Changes Physical Changes Physical Changes affect some properties of matter but no new substances are produced Movement Thermal (temperature) Electrical Light and Sound

Movement Thermal Electrical

Types of Changes Chemical Changes and Reactions Chemical changes produce new substances Pure substances (reactants) are turned into different substances (products) Chemical reactions are important because they create energy and new materials

Photosynthesis Rust Combustion