Chemistry: the study of matter and changes that are associated with it. ex: physical and/or chemical

Properties of Matter: matter is anything that has mass and occupies space.

5 Indicators of a Chemical Change:

• emission of light and/or heat

• formation of a gas

• formation of a precipitate

• change in color

• emission of odor

All matter can be classified into three groups:

• elements

• compounds

• mixtures

States of Matter:

Solid

• has a definite volume and shape

• the particles of a solid are packed close together in relatively fixed positions

• particles are held by very strong forces between them

• the particles of a solid simply vibrate about a fixed position

Liquid

• has a definite volume but no definite shape

• assumes the shape of the container

• the particles of a liquid are held close together but because they are moving faster they can overcome the attractive forces and move one another

Gas/Plasma

• has neither a definite shape nor definite volume

• composed of particles that move very rapidly and are at a great distance from one another, making the attractive forces between the particles very weak

• plasma: a high-temperature physical state of matter in which atoms lose most of their electrons

• can be found in lightning, stars, and some TV screens

Endothermic vs Exothermic

Endothermic

definition: a reaction that releases energy to the surroundings, causing the reaction mixture and its surroundings to become hotter

examples: burning/combustion, neutralization, and displacement

Exothermic

definition: a reaction in which energy is absorbed from the surroundings, causing the reaction mixture and its surroundings to become cooler

examples: evaporating or melting