3. Compounds are the
combination of atoms
with a specific ratio.
4.Chemical reactions
involve reorganization of
the atoms.
Thomson's
atomic model
Raisin in the
plum pudding
Experiment with
cathode ray and
conclude that
matters consist of
negatively
charged particle
called electron.
Calculate mass/charge ratio of electron =
-5.686 * 10^12 kg/C
Rutherford's
atomic model
Suggest the atomic nuclear model
from the results of bombardment
gold foil with alpha particles.
Atom consists of electrons which
move around the positively
charged center called nucleus.
atomic
planetary
model
Atom is mostly empty space. The
size of nucleus is very small
compare to the atom itself.
Quantum View
of Atom
Bohr's
model
Bohr proposed that atom has energy
levels as circular orbits. Electrons
move as wave in a specific energy
levels. Electrons can transfer to
different energy levels when they lose
or gain energy.
Each energy level has
specific quantum
number (n) starts from
1,2,3...
Erwin Schrödinger used
Quantum Mechanics to explain
the energy state in the
hydrogen atom.
The equation is called
wave function. A specific
wave function is often
called an orbital.
Quantum number and
atomic orbitals
the principal quantum
number (n)
n = 1,2,3... small n, small size, close
to nucleus, low energy
the orbital angular
momentum quantum
number (l)
give different
shape of orbital
s p d f
orbitals
the magnetic quantum
number (ml)
give different
orientation of orbital
the spin quantum
number (ms)
represent spin of electron. Only two possible
values : +1/2 and -1/2
Wave Particle
Duality
In subatomic level, energy and matter
cannot be distinguished. They have both light
and particle properties.
light consists of particles
called photon. Photon
travels as wave.
Matter consists of atom
and subatomic particles.
Subatomic particles such
as electrons travel or
move as wave.