CHEMISTRY ABC THE BASICS
CHEMISTRY ABCTHE BASICS
SUB ATOMIC PARTICLES
PROTONS
POSITIVE CHARGE
NEUTRONS
NO CHARGE
ELECTRONS
NEGATIVE CHARGE
+
Mgz
AMASS NUMBER
ATOMIC NUMBER
Mg12
24
A = Z + N
Number of neutrons = 12
24 = 12 + N
WHY THEY LOOK AND BEHAVE SO DIFFERENT
EVEN THOUGH THEY ARE MADE OF THE SAME THREE
BASIC PARTICLES?
BECAUSE THE PHYSICAL AND CHEMICAL
PROPERTIES DEPENDS UPON THE AMOUNT OF
THEM
Fe26
56
H1
1
C6
12
He2
4
How many?
118
92H
U
1
92
Dalton’s atomic theory
Atoms are the smallest and indivisible part of
matter.
They are considered as building block of matter.
Everything around us in the universe is made up
of atom.
Any substance composed of only single type of atom constitutes
an element.
MODERN ATOMIC THEORY
Atoms are divisible and destructible.
They are divisible into sub atomic particles such as electrons, protons and neutrons.
Atoms of the same element may not be identical in all respect.
Atomic Models
Rutherford’s Atomic Model
Bohr’s Atomic Model