Atoms and molecules

4. Atoms are building block of all matter

5. Atomic radius is measured in nanometres (1 m = 10⁹nm)

6. Individual atoms can be observed using Scanning Tunnelling Microscopes

7. Each element has a name and a unique symbol

8. Rules for assigning symbols for atoms of various elements

a. The abbreviation used to represent an element is generally the first letter in capital of the English name of element

English name of element	Symbol
Hydrogen	H
Boron	B
Oxygen	O
Nitrogen	N
Fluorine	F

b. When the names of two or more elements begin with the same initial letter, the initial letter followed by the letter appearing later in the name is used to symbolize the element

Name of element	Symbol
Barium	Ba
Bismuth	Bi
Bromine	Br
Silicon	Si
Cadmium	Cd

c. Symbols of some elements are derived from their Latin names

Name of element	Latin name	Symbol
Sodium	Natrium	Na
Potassium	Kalium	K
Copper	Cuprum	Cu
Iron	Ferrum	Fe
Gold	Aurum	Au
Silver	Argentum	Ag

ModStudy

Atoms and molecules