3.1Matter Defined

   Matter is anything that has mass and takes 

up space. Matter is not only visible material

for example: air is not seen yet it is still 

matter.

3.2Physical States of Matter

   Solids have definite shape and a definite volume.

Liquids have a definite volume but no definite

shape. They take on the shape of the container in

which they reside.

Gases have no definite shape and non definite 

volume. They acquire the shape and volume of the 

container in which they reside.

3.3 Substances and Mixtures

   A substance is a type of matter with a definite

composition. It is either an element or a compound.

A mixture is a material consisting of two or more

substances. The mixture can be homogeneous   which

means it is uniform throughout and has the same

properties throughout or it can be heterogeneous 

which means it has two or more distinct phases.

A phase is a homogeneous part of a material

separated from the other parts by some physical

boundary.

3.4 Elements

    An Element is a substance which cannot be further 

broken down into simpler substances by chemical

means. 

The smallest particle of an element that can exist is

an atom.

3.5 Distribution of Elements

   Elements are distributed differently depending upon

what is under examination. For example; if we are 

discussing the distribution of elements on the surface of 

the earth then the distribution looks like this: 

3.6 Names of the Elements

   The names of many of the elements are derived from

Greek, Latin, and German names given to them by

chemists in the earlier centuries. The newer elements

are often named to commemorate a famous scientist.

3.7 Symbols of the Elements

   Symbols are abbreviations for each element.

The rules governing the symbols are: 

1. Symbols are composed of one, two, or three letters.
2. If one letter is used it is capitalized.
3. If two or three letters are used only the first is capitalized.

* It is critical to know the symbols because the 

language of chemistry is based upon these symbols.

3.8 Metals, Nonmetals and Metalloids

   There are three types of elements; metals, nonmetals, 

and metalloids. 

Metals are solids at room temperature except for 

mercury. Metals are good conductors of heat and 

electricity and are good for light reflectors. Metals 

are malleable, that is easily rolled or hammered 

into sheets. Metals are ductile, that is they can be 

drawn into wire. Metals have high melting points 

and a high density. Metals have a tendency to 

combine with nonmetals and form ionic compounds.

Nonmetals are not lustrous i.e. they are not shiny. They 

are electrical insulators and do not conduct heat well.

Nonmetals combine with each other to form molecular

compounds. 

Metalloids have properties between those of metals and

nonmetals. These elements are the basis of the 

semiconductors used in electronics.

The following links are to two areas where the periodic

table are displayed with a large amount of information on

each element.*We urge you to visit these sites and use

them as reference in your studies:

Web Elements ( Mark Winter, U. Sheffield, England )

Periodic Table ( Chris Heilman, Phoenix College )

3.9 Compounds

   A compound is a substance made up of two or more 

elements in definite proportion by mass. Compounds

can be decomposed into simpler substances by 

chemical reactions. Two different types of compounds

exist, ionic and molecular covalent.

Molecules are the smallest unit of a compound 

composed of two or more atoms.

An ion is a charged atom or group of atoms.

Ionic compounds are substances formed by the 

attraction of two or more oppositely charged

ions.

3.10 Elements That Exist as Diatomic Molecules

   The following elements are made up of molecules 

that are formed by two atoms of the element. 

• Hydrogen
• Nitrogen
• Oxygen
• Fluorine
• Chlorine
• Bromine
• Iodine

3.11 Chemical Formulas

   A chemical formula shows the symbols and the 

ratios of the atoms in the compound. When the 

formula contains more more than one atom of the

element, the number of atoms is written as a 

subscript to the symbol.

When there is only one atom of an element in a 

formula the number 1 is not written.

When a formula contains more than one of a 

group of elements, the group is contained by a

parenthesis and a subscript is written after the 

parenthesis.

The arrangement of atoms of a compound is not 

shown in formulas that show only the composition

such as H₂SO₄.

3.12 Mixtures

   A mixture contains two or more substances that 

can occur in any proportion and that can be 

separated by physical means.

A homogenous mixture is composed of two or more 

substances that are uniformly mixed in composition

throughout.

A heterogeneous mixture is one which is separated 

into two or more different phases.