ATOMS

DEMOCTRITUS

ATOMS MODEL

• He formulated the atomic theory for the cosmos
• He was well known to aristotle but was hated by plato
• The first famouse scientist.
• His experiment was the "BIG THOUGHTS"

ARISTOTLE

EARTH WIND FIRE WATER ELEMENTS

• His experiment was the light and the ability of humans to see color
• He believed that all substances were made of fire,water,air and earth
• The four categories of Aristotle's philosophy were;logic, theoretical,practical and poetical philosophy.

DALTON

BILLIARD BALLS

• His experiment was observing chemical reactions
• His atomic theory said that the elements consisted of tiny particles
• The balls were round in shape

JJ THOMSON

PLUM PUDDING

• Made a piece of equipment called a cathode ray tube
• It is a vacuum tube where all the air has been pumped out
• The cathode ray carry energy and can do work
• Travel in straight lines in the absence of an external field.

RUTHERFORD

POSITIVELY CHARGED NUCLEUS MODEL

• His experiment was the gold foil
• Electrons revolving around the nucleus in a certain path are known as orbits.
• The extremely small, negatively charged electrons are distributed around the nucleus and balance the charge of it.
• According to the Thomson model, electrons and protons are equally distributed throughout the atom. So, if high velocity alpha particles are bombard on an atom, there would be very little deflection in particles.

MILLIKAN

THE OIL DROP EXPERIMENT

• His theory was the charge of an electron/mass
• The charge on the oil drop is produced by the interaction of the oil drop with the X ray.
• The X ray interacts with the free falling oil drop and give away its charge to the oil drop.
• The potential difference between these electrodes is in the range of thousands of volts so that the oil droplet could not free fall when subject to the electric field.

CHADWICK

PROTON NEUTRON MODEL

• His experiment was to find the existence of a particle that has no charge at all
• James predicted the atom would have a neutron.
• He established that atomic number is determined by the numbers of protons in an atom.
• He also discovered the fourth subatomic particle,the neutron.