Transcript Atomic Models

Atomic Models
8th Grade
Dalton’s Model (1807)
Thompson’s Model (1904)
Positively
charged
material
Electrons
Thompson’s Model
“Plum Pudding” model
 Electrons were just mixed into the
positive material, the same way that
chocolate chips are mixed into ice
cream.
 The electrons mixed with the positive
material, giving the atom a neutral
charge.

Rutherford’s Model (1908)
ATO
The atom is mostly
empty space where
the electrons travel.
Small, dense positively
charged nucleus
Electrons travel around
the nucleus the same
way planets travel
around the sun.
Bohr’s Model (1913)
Bohr’s Model
 Nucleus
has both protons and
neutrons
 Electrons travel in definite paths
around the nucleus
 Electrons can jump from one level
to another, similar to jumping from
one rung on a ladder to another.
Current Atomic Model
Broglie & Schrodinger (1920)
Electrons
are found
in electron
clouds
around the
nucleus.
Parts of an atom
Electrons are negatively
charged particles located in
electron clouds around the
nucleus. The size & number
of electron clouds determine
the size of the atom.
The nucleus is the small,
dense, positively charged
center of the atom. Most of
the atom’s mass is found here.
The diameter of the nucleus is
1/100,000 the diameter of the
atom.