Download Matter and Atoms

MATTER AND ATOMS
By Mr. M
Macroscopic refers to large scales like the
universe
Microscopic refers to small scale that we
cannot see with our eyes alone
Submicroscopic is so small we cannot see it
with a microscope or other tools
 Everything
is made of matter and energy
 The universe breaks down into galaxies that
break down into solar systems that break
down into celestial bodies that break down
into environments/ecosystems that break
down into creatures that break down into
organs/tissues that break down into cells
that break down into organelles that break
down into chemical compounds that break
down into atoms that break down into
subatomic particles that break down into…
 Chemicals
can be broken down into different
categories
 The breakdown is based on how the
chemicals can be separated and what they
are made of
Physical: can be observed without changing the identity of the
substance
What are some
physical
properties?
 color
 melting and
boiling point
 odor
Some physical
changes would be
 boiling of a liquid
 melting of a solid
 dissolving a solid
in a liquid to give
a homogeneous
mixture — a
SOLUTION.
 Tearing something
in half
 Painting something
 Chemical
properties are
hard to see
 Reactivity
 Toxicity
 Entropy
 Enthalpy
 Stability
 Chemical
change
or chemical
reaction —
transformation of
one or more atoms
or molecules into
one or more
different
molecules.
 Burning
 Nuclear fission
 Heat
 Light
 Gas
made
 Precipitate (a new
solid that appears)
 Color change

Examples:

melting point
physical

flammable
chemical

density
physical

magnetic

tarnishes in air
physical
chemical
MATTER
yes
MIXTURE
yes
PURE SUBSTANCE
Is the composition
uniform?
Homogeneous
Mixture
(solution)
Colloids
no
Can it be physically
separated?
no
Heterogeneous
Mixture
yes
Can it be chemically
decomposed?
Compound
Suspensions
Element
no
 Everything
is made of atoms
 Compounds are made of different atoms
 Elements are only one type of atom



Thus for every element there is a different type
of atom
All of the elements (atoms) are listed on the
periodic table
Each element can have different forms
We say there are three states of matter;
however, ….
 _______ — have rigid shape, fixed
volume. External shape can reflect the
atomic and molecular arrangement.
 Reasonably well understood.
 _______ — have no fixed shape and
may not fill a container completely.
 Not well understood.
 _______ — expand to fill their
container.
 Good theoretical understanding
 The
idea of the atom starts in 460 BC, but
the actual terminology and acceptance of
the atom does not begin until late 1700s
 Plum
pudding
 Billiard
Ball
 The
nucleus is the center of the atom and
the parts of the nucleus are called nucleons

Protons and neutrons are in this area
 The
outer layers of the atom have been
called orbits, rings, energy levels, shells, and
orbitals.

Electrons are in this area
 You
are expected to master electrons,
protons, and neutrons…. If you think that is
too much just look at the real parts
 To
find out how many electrons, protons, and
neutrons an atom has you need a periodic
table
 There are two (sometimes three numbers if a
charge is included) that you need in each
periodic table tile block.
 The
atomic number is actually the number of
protons. If you add or subtract a proton you
change the atomic number and thus the
element’s identity
 Protons have a mass of one amu
 Protons have a charge of positive 1
 The
mass number is actually the neutrons
plus the protons, so you must take the mass
and subtract the protons to find neutrons

Atomic mass – atomic number
 Neutrons
have a mass of 1 amu
 Neutrons have no charge
 Neutrons are the glue of the atom
 Atoms are held together by “the strong
force”, weak forces, and electromagnetic
 Electrons
are assumed to be equal to protons
unless a charge is given
 If a charge is present you find electrons with




Atomic number – charge
Example: H+1 is hydrogen with a charge of plus 1
so it is 1 -1 = 0 electrons
H -1 has a charge of negative one so 1- - 1 =2
electrons
H with no charge is just 1 electron
 Mass
of 0
 Charge of negative 1
 An
element of molecule with a charge
 Charges are given in the upper right hand
corner
 H+
or H-1
 Different
masses of the same element:
Hydrogen-1 (1H) or hydrogen-2 (2H) or
hydrogen-3 (3H)
 caused by different amounts of neutrons
 Many are radioactive
 The mass on the table is an average of the
isotope masses based on the percent
abundance of each isotope
 If
hydrogen 1 is 99 percent of all hydrogen
and hydrogen 2 is 1 percent of all hydrogen,
find the average atomic mass
 (.99 X 1 amu) + (.01 X 2 amu) = 1.01 amu