Page 101 - Science Class 6 Times Publication

This is due to evaporation of water
from the washed clothes.

3. Water in the river comes from
melting of snow of Himalayas.
Melting of snow is due to the
heat from the sun.

4. Metals are melted into liquid
by heating them and changed
into different shapes. Thus, ornaments, statues, etc are made
from metals.

Element and compound

Some substances are composed of only one type of atoms whereas
other substances are composed of two or more types of atoms. The
substances which are composed of only one type of atoms are called
elements. Nitrogen, oxygen, hydrogen, calcium, iron, etc are examples

of elements. There are 118 elements discovered so far. Out of them, 92
elements are found in nature and 26 elements are produced arti cially
in laboratories. Elements are found in three states, i.e. solid, liquid
and gas. Element like bromine, mercury, caesium, francium and
germanium are found in liquid state. Eleven elements are found in
gaseous state. Nitrogen, oxygen, hydrogen, etc are some examples.
Rest of the other elements are found in solid state. Based on the
properties, elements are further divided into metal, non-metals and
metalliods.

Metals
The elements which conduct heat and electricity are called metals.
For example, iron, aluminium, copper, etc.

Non-metals
The elements which cannot conduct heat and electricity are called
non-metals. For example, carbon, phosphorus, oxygen, hydrogen,

nitrogen, etc.

Times' Crucial Science and Environment 97 Book 6