What is The Difference Between Distance And Displacement:

S.No	Distance	Displacement
1.	It is the actual distance travelled by an object in the given time.	It is the shortest distance between the initial and final positions of the object in the given time.
2.	It is a scalar quantity.	It is a vector quantity.
3.	The distance travelled by an object in a given time is never negative or zero, but is always positive.	The displacement of an object in a given time can be positive, zero or negative.
4.	The distance travelled by an object in a given time is either equal or greater than displacement but never less than displacement.	The displacement of an object in a given time can be equal or less than distance travelled but never greater than distance travelled.
5.	The distance covered by an object between two positions can have many values, depending upon the path followed.	The displacement of an object between two positions has a unique value.
6.	The distance travelled by the object between two positions tells the type of path followed.	The displacement of an object between two positions does not tell the type of path followed.

What is an Element?

Elements: An element is defined as the pure substance which is made of only one kind of particles. These particles may be atoms or molecules.

• Carbon sulphur, iron, lead, gold, mercury, hydrogen, oxygen, and nitrogen are some examples of familiar elements.
• Iron, gold, copper etc contain single atoms as constituent particles held together.
• Hydrogen, oxygen, nitrogen etc consists of molecules, comprising of two atoms combined together.
• The no of elements known to-date is 114. Out of these elements known, 92 are occurs in earth’s crust and the left one have been prepared artificially in the laboratory through nuclear reactions.

Types of elements:

Elements are classified as:

Metals: Metals are those elements which possess lustre (shining appearance), reflects light, are good conductors of heat and electricity, are malleable (hammered to thin sheets) and ductile (drawn into wires), exist as solid at room temperature (except mercury), possess high density.

• Example: iron, copper, silver, gold etc.

Non-metals: Non-metals are those elements which does not reflects light, poor conductors of heat and electricity (except graphite), does not possess malleability and ductility, do not have lustre (except iodine), exists in all the three states.

• Example: carbon, hydrogen, oxygen, nitrogen etc.

Metalloids: Metalloids are those elements which exhibits the property of both metals and non-metals.

• Example: Arsenic, antimony and bismuth.

What is Science?

Science is nothing but it is getting the deep knowledge of nature and natural phenomena. In other word the deep and systematic study of whatever happens in this physical world is called science. 

The word science is derived from the Latin verb ‘scientia’ which means ‘to know’. The Sanskrit word vijnana and the Arabic word Ilm convey the similar meaning, namely ‘knowledge’.

The knowledge which humans have collected through their observations and experiments, when organized systematically is called Science.

The different definitions of Science given by various scientists are:

Albert Einstein: Science is not just a collection of laws, a catalogue of unrelated facts. It is a creation of human mind. With its freely invented ideas and concepts.

Bruce Lindsay: Science is a method of describing, creating and understanding human experience.

Neils Bohr: The task of science is both to extend the range of our experience and to reduce it to order.

Gerald Holton: Science is ever unfinished quest to discover all facts, the relationship between things and the laws by which the world runs.

Science is divided into many branches:

Physical Sciences: The Science in which we study about non living things is called physical sciences. For example, Physics, Chemistry, Geology, Astronomy, Geography, Astrology, Oceanology etc.

Biological Sciences: The science in which we study about the living things is called Biological Sciences. For example, Botany, Omithology, Anthropology, Entromology, Zoology, Forensic science etc.