Chemistry, Chapter 1Intro to Chemistry Matter and ChangeProperties Of Matter

Chemistry

The study of matter and the changes it undergoes

Classifying Matter

Matter- anything that has mass and volume

All matter is composed of tiny moving particles called

atoms = smallest unit of an element that keeps the

properties of that element

All matter can be broken into two categories:

Pure Substances

Mixtures

Pure Substance- substance that has a fixed composition. Can

only be broken down by breaking chemical bonds.

Fixed composition- a substance that has the same

proportion by mass every time. EX: H2O vs H2O2

Element- pure substance made of only one type of atom: EX:

Au, F, Sn, He

Molecule- two or more atoms of the same type bonded

together(H2 , O3)

Compound- substance composed of two or more types of

atoms that are chemically bonded [NaCl, NaHCO3, MgSO4]

Mixtures Mixtures- blend of two or more pure substances-

NOT chemically combined Mixtures do not have a “fixed composition” , the components

of the mixture can be present in any amount.

Can be separated by physical processes

Heterogeneous- not the same throughout, each part has different properties. Ex: Blood( red blood cells, whites blood cells, plasma), sand, concrete, granite

Homogeneous- the same throughout. Ex: sugar dissolved in tea, salt water, air, soda.

Properties of Matter Chemists use characteristic properties of a substance

to:

tell substances apart

Identify substances

separate them from other substances

Certain properties define an entire group of substances-

EX: metals are good conductors of electricity

EX: solid non-metals have low luster

Types of Properties

Extensive- a property that depends on the amountof matter present- think of it this way if an extensive

property changes so does how much matter you have!

EX: volume, mass, length

Intensive- a property that does not depend on the amount of matter present

Ex: density, boiling point, ability to conduct, color, odor, luster, malleability, hardness