Symbol of elements
Symbol of Lithium
Li
Helium
2
Positively charged particle of the atom
Protons
Beryllium
(2,2)
Hydrogen
Symbol of Oxygen
O
Boron
4
The term represented by A
Atomic mass number
Fluorine
(2,7)
Aluminium
3
Symbol for Silicon
Si
Neon
10
Argon
Carbon
(2,4)
Nitrogen
3
Symbol for Sodium
Na
16
Atoms of an element which have the same atomic number but different mass number.
Isotopes
Magnesium
(2,8,2)
Chlorine
1
Symbol for Potassium
K
Calcium
20
The atomic model proposed by J.J. Thompson wherein atom as a positively charged sphere into which negatively charged electrons were embedded.
Plum-pudding model
Phosphorus
(2,8,5)
Silicon
4