atomic_structure_and_periodic_table_notes.pptx - Atomic...

Atomic Structure and Periodic
Table Notes

1. What are Atoms?

2. 400 BC Democritus was the first
scientist to suggest that all matter is
composed of tiny, individual particles
called atoms. ( Atomos )

3. Elements are made up of atoms.
Atoms are the smallest particle into
which an element can be divided and
still retain its identity.
An element is matter made
up of only ONE type of
atom.

4. The Atomic Theory was proposed
by John Dalton in the late 1700’s.
This theory was based on the
experimentation and data of other
scientists.

5. Atomic Theory
1.All matter is made of atoms
2.Atoms cannot be divided
3.Atoms of a particular element are
exactly alike
4.Atoms can join with other atoms to
create new substances .

5. Since then, other scientist have
expanded on our understanding of atoms
in the following ways.
-1897
JJ Thompson
used the cathode ray
tube to find negative particles within the
atom , which he named
electrons
. (He
called his model the Plum pudding model)

-Early 1900’s
Rutherford
directed a beam of