MATTER
What is Matter?
 Must
have mass
 Occupies
space (has volume)
Density
 Because
all matter has mass and
volume, all matter has density.
D
=
M
V
Law of Conservation of Matter

Matter cannot be
created or
destroyed

When 400 grams of
wood are burned only
about 30 grams of
ash remain.

What happened to the
missing matter?

During a
chemical
reaction
matter is
conserved
States of Matter

Matter can
exist in three
basic states:



Solid (s)
Liquid (l)
Gas (g)
A Fourth State of Matter?

Plasma

Occurs when the
atoms of matter have
been stripped of their
electrons.
Basic Types of Matter
Pure Substances
Elements
Elements
•
Made up of atoms of one specific type
•
Cannot be broken down further by a
chemical reaction
•
Have specific physical and chemical
properties.
The Periodic Table of Elements
•
Each element has its
own atomic number
•
Atomic number tells
us the number of
protons in that
elements nucleus.
Examples of Elements

What elements can you find in the
classroom now?

What elements are
important in the food
we eat?
Where Do We Get Elements?

Obtained in
nature in their
pure state.

Some elements
are combined
together in
compounds and
are separated
out through
chemical
reactions.

Some elements don’t
exist naturally, and
are man-made
through nuclear
bombardment
reactions
Elements and Their Symbols

Elements have either
one or two letters
when they are written
as a symbol.

If two letters, the
second letter is
written lower case.
(Ex: Write Cu for
copper not CU)

Usually it is pretty easy to match an
element to its symbol (Ex: Neon = Ne)

Sometimes the symbol is derived from a
Latin name for the element.

Ex: Au = gold (comes from Latin word aurum)
Tricky Elements

Here are some of the
harder elements to
match their name to
their symbol.











Na = sodium
K = potassium
Fe = iron
Cu = copper
Sb = antimony
Sn = tin
Pb = lead
Hg = mercury
W = tungstun
Au = gold
Ag = silver
Phases and Elements

Under standard conditions,
most elements exist as solids.

The Gases:
 H, He, Ne, Ar, Kr, Xe, Rn,
O, F, Cl

The Liquids:
 Hg, Br
Diatomic Elements

Two atoms of the
same element joined

Bromine, Iodine,
Nitrogen, Chlorine,
Hydrogen, Oxygen,
Fluorine

BrINClHOF
Compounds
Compounds

Most elements in nature do not exist in
their pure state, but in compounds.
Compound = Two or more different elements
bonded together chemically
Ex: C6H12O6, MgCl2, CH4, NO2, CO2, NaCl
Law of Definite Proportions
•
Elements in compounds
have definite fixed
proportions by mass.
Getting New Properties

Compounds have different chemical and
physical properties than the elements that
make them up.
- Sodium (Na)
Toxic, reactive metal
that will explode in
water
- Chlorine (Cl)
Brown toxic gas that
was used as a
chemical weapon to
kill people in WWI
Sodium Chloride (NaCl)
White edible crystal,
and salt for my french
fries!!
Focus Question
 What
are the differences between
elements and compounds?