CORC 1322 MAIN PAGE

MATTER

Introduction
Atoms and Molecules

ATOMIC STRUCTURE

Introduction
Electrons
Protons
Neutrons

REACTIONS

Introduction
Bonds and Octet Rules
Chemical Equations
The Mole

SOLVING PROBLEMS

Density
Conversions

VISUAL AIDS

Functional Groups
Periodic Table

QUIZZES

Practice Quiz I
Practice Quiz II
Practice Quiz III

Introduction

Anything that can be weighed is matter. Rocks, water, wood, smoke, stars, air, and sand are all examples of different types of matter.

There are three different states in which matter can exist in the universe.

 Solid Keeps its own shape and own volume, independent of the container Liquid Takes on the shape of the container, but keeps its own volume Gas Takes on both the shape and the volume of the container

Scientists classify matter into two main categories: compounds and elements. A compound is matter that can be broken down into other types of matter, while an element is matter that cannot.

Liquid water is a compound because water can be separated into hydrogen gas and oxygen gas. But oxygen gas and hydrogen gas are elements because they cannot be broken down into other types of matter. Note, however, that oxygen gas (O2) and hydrogen gas (H2) are diatomic molecules (two atoms per molecule) and that, under certain conditions, they can be broken down into oxygen and hydrogen atoms, respectively.

A more general way in which scientists classify matter is substances and mixtures. A substance is any amount of matter, element or compound, of only one type. Pure water and pure table salt (sodium chloride) are substances because each consists of only one type of matter.

A mixture is any amount of matter that is a combination of more than one type of matter. A solution of table salt in water is a mixture because it contains two different types of matter: water and table salt. The different types of matter in a mixture share the same space but retain their individual identities.

Properties of Matter

Matter can undergo physical and chemical changes. A physical change does not alter the identity of matter but a chemical change does. The following table provides examples of physical and chemical properties and changes, and an illustration follows.

 Type of Matter Example of Physical Property/Change Example of Chemical Property/Change Iron nail Gray color, smooth, can be cut in half Rusts when exposed to air or left in the rain Banana Yellow, squishy, can be peeled Digestable inside the stomach Wood Hard, floats in water, can be painted blue Turns to ash when burning in a fire Copper Orange color, conducts electricity, can be ground into powder Dissolves in acid Neon gas Glows when exposed to electricity, can be compressed into a tube Does not react to matter, no known chemical changes

 Physical Change Iron nail cut in half Chemical Change Iron nail rusting when left in the rain