Chemistry Chapter 3 Definitions

Matter: Anything that takes up space and has mass

3 states of matter: solid, liquid, gas

2 types of solids: amorphous and crystalline

Solid molecular motion: oscillation/vibration about fixed point

Liquid and Gas atomic/molecular motion: free to move relative to one another

Solid and Liquid atomic/molecular spacing: close together

Gas atomic/molecular spacing: far apart

Solid shape: definite

Liquid and Gas shape: indefinite

Solid and Liquid volume: definite

Gas volume: indefinite

Solid and Liquid compressibility: incompressible

Gas compressibility: compressible

2 types of pure substances: element or compound

Element: a pure substance that cannot be broken down into simpler substances

Define Helium: element

Compound: a pure substance that is composed of two or more elements bonded in a fixed ratio.

Define H20: compound

Pure substance: composed of only one type of atom or molecule

Mixture: composed of two or more different types of substances not chemically united, mixed together in varied proportions

2 types of mixtures: homogenous and heterogenous

Homogenous: having the same composition throughout

Number of phases in a homogenous mixture: 1

Hetergronous: having a composition that varies from region to region

Number of phases in a heterogeneous mixture: 2

Physical property: property a substance displays without changing its composition

Odor type of property: physical

Chemical property: property a substance displays through changing its composition

Change of states type of change: physical

Physical change: The appearance of matter may change but the composition does not.

Water type of change: physical

Chemical change: the composition of matter changes.

When does matter undergo a chemical change: when it undergoes a chemical reaction

Law of conservation of mass: Matter cannot be created nor destroyed

Matter is always what?: conserved

During a chemical change what must the sum of the mass of the reactants equal?: the sum of the mass of the products

Law of conservation of energy: Energy cannot be created nor destroyed

Energy: the capacity to do work

Work: the result of a force acting on a distance

Types of energy (KEPTC): kinetic, electrical, potential, thermal, chemical

Energy is always what?: conserved

Units of energy: Joules, calories, nutritional Calories, kilowatt/hour

kWh: kilowatt/hour

2 types of chemical reactions: endothermic and exothermic

Endothermic: chemical reactions that absorb energy

Exothermic: chemical reactions that emit energy

The temperature of the matter is related to what?: random motions of the molecules and atoms

Heat: the exchange of thermal energy caused by a temperature difference

Temperature: the measure of the thermal energy of matter

More motion of atoms: more temperature

3 scales of temperature measurement: kelvin, Fahrenheit, and Celsius

Heat capacity: The temperature change that matter undergoes upon heat absorption is related to the heat capacity of the substance composing the matter.

Heat capacity is simple: the amount of heat energy you need to raise the temperature of the matter by a degree.

More matter in terms of heat capacity: higher heat capacity