Download What is matter made of?

MATTER
&
ATOMS…
WHAT IS MATTER?
 Matter
describes all of the physical
substances around us: your table, your
body, a pencil, water, air or all solids liquids
& gasses.
 Anything that has mass and volume (takes
up space)
 Made up of different kinds of atoms
The BIG Idea???
Matter
is made of
ATOMS!!!
Why use MODELS for
ATOMS?
 In
the case of atoms, scientists use
large models to explain something
that is very very small
 (invisible to the human eye)
Atomic Theory
Atomic Theory
The Atomic Theory is the idea of what atoms
look like and how they behave.
Democritus
 Said
an object could be cut
in half again & again until
it became too small that it
could no longer be divided.
Called this indivisible particle
the “ATOM”
 Atoms could not be divided!

John Dalton

1803 published Atomic Theory

All matter is made of invisible
particles called ATOMS.
Atoms are invisible, indivisible, and
in constant motion.
Atoms of the same kind of matter are identical.
2 or more Atoms joined together make up a
Molecule.
Compounds consisted of 2 or more different
kinds of atoms combined together.




J.J. Thomson 1897
Discovered negative charged
electron
 Plum pudding model
 Atom made of a positively
charged material with the
negatively charged electrons
scattered through it.

Ernest Rutherford
 Discovered
the Atom is mostly
empty space
 Small nucleus that contained
positively charged protons
 Negative electrons scattered
around the outside
Niels Bohr
 Solar
System Model ~ 1913
 Said that electrons orbit the nucleus along
certain paths called energy levels or
orbitals.
 Chemical properties are determined by the
electrons in the outermost orbit.
Werner Heisenberg 1926
 Stated
that the exact position of an electron
can never be precisely known.
 Spherical CLOUD of varying density
 The Electron Cloud Model
James Chadwick 1932
 Discovered
a particle without a charge.
 The Neutron located in the Nucleus with the
Proton
ATOMIC MODEL
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
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Each Scientists studied the work of
previous scientists, researched,&
made new discoveries building upon
each others work.
This has led to the current model of
the Atom.
Will it change again??? HOW &
WHY?