Page 99 - ICSE Chemistry 8

ELEMENTS AND THEIR SYMBOLS

An element is the simplest form of a pure substance which is made up of only one kind of atom. It is
represented by a chemical symbol. For example, oxygen is represented using the chemical symbol O.

A chemical symbol is the representa on of an atom of an element. For example, one atom of oxygen is
represented by a single O. The names of diff erent elements are wri en in English, German, La n or Greek.

Each element has been allocated a unique symbol by the Interna onal Union of Pure and Applied
Chemistry (IUPAC). The symbols used to represent elements are usually the short forms or abbreviated
names of these elements.

There are certain rules for representa on of elements.
• Symbols of most of the elements are denoted
Know Your Scientist
by the fi rst le er of their English names.
They are represented by a capital le er. For Jöns Jacob Berzelius (1779–1848) was the fi rst
example, the symbol of nitrogen is N and that to use le ers as symbols for element, which
we use ll today.
of carbon is C.

• In some cases, more than one element has
a name star ng with the same le er, for example, carbon and chlorine. In such a case, carbon
is represented by the le er C and chlorine is represented by any two le ers of its name, i.e., Cl.
When a symbol is represented using two le ers of the elements name, we write the fi rst le er in
the upper case followed by the second le er in lower case.
• Some elements are assigned symbols on either their scien fi c or La n, Greek or German name.
For example, the symbol of sodium, which is Na, is derived from its La n name natrium.

Names and symbols of some elements are given in the tables below.
Table 5.1: Symbols Derived from the First Le er of the Names of Elements

Element Symbol

Boron B

Carbon C

Fluorine F

Hydrogen H
Iodine I

Nitrogen N

Oxygen O

Phosphorus P

Sulphur S

Uranium U

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