Download Created by Campesi, SMS

ATOMIC
THEORY
Created by Campesi, SMS
The smallest particle into
which an element can be
divided and still be the same
substance is an
ATOM
An explanation for
hypotheses and
observations that have
been supported by
testing is a
Theory
Democritus, Greek
philosopher, said that you
would eventually end up
with an “uncutable” particle
that he called an
ATOM
Billard ball model
Dalton developed the
atomic theory based on
experiments!
Dalton Theory
Atoms are small particles
that cannot be created,
divided, or destroyed.
Atoms of the same element
are exactly alike, and atoms
of different elements are
different.
Dalton Theory
Atoms join with other
atoms to make new
substances with new and
different properties.
Thomson Theory
Thomson discovered that
there are small particles
inside the atom.
Atoms can be divided into
even smaller parts.
Thomson Theory
Thomson found the
electron.
Plum pudding model or
chocolate chip ice cream.
Rutherford Theory
Rutherford presents a new
atomic model
Proposed that in the
center of the atom is a
tiny extremely dense
positively charged region
called the NUCLEUS
.
Bohr Theory
Bohr suggested that
electrons travel around
the nucleus in definite
paths.
Electrons can jump levels.
Modern Theory
Electrons do not travel in
definite paths as Bohr
suggested.
Regions inside the atom
where electrons are likely
to be found are called
electron clouds.
Inside an Atom
Proton-positively charged
particles inside the nucleus
with a mass of 1 amu.
Protons are what make an
atom what it is.
Atomic number is the
number of protons.
Neutron-neutral particle
inside the nucleus with a
mass of 1 amu.
Neutrons just make an
atom “fat.”
Electrons-negative chargein the electron cloud-almost
no mass.
Atom is neutral-equal
number of protons and
electrons so they cancel
each other out.
If protons and electrons
are not equal it becomes
a charged particle called
an ion.
Isotopes are atoms that
have the same number of
protons but have different
numbers of neutrons.
The element does not
change as long as it has
the same number of
protons.
Isotopes can be unstable
or radioactive.
The isotopes of an element
share similar properties.
Mass number is the
number of protons and
neutrons in an atom.
Naming isotopesHydrogen-1, hydrogen-2,
carbon-12, carbon-14
Atomic mass is the
weighted average of the
masses of all the naturally
occurring isotopes of an
element. ATOMIC MASS IS
NOT A WHOLE NUMBER.
Number of protons
Number of Electrons.
Subtract atomic number
To get # of neutrons
Number of protons= 3
Number of electrons= 3
Round to nearest whole
Number of neutrons= 4
Forces in the Atom
Gravity between all objectssmall mass in an atom small
gravity.
Electromagnetic forceopposites attract, holds
electrons in orbit around the
nucleus.
Strong force- hold the
nucleus together despite
the electromagnetic
force.
Weak force- plays a role in
radioactive atoms.