SIR SADIQ’S NOTES FOR IX & X
CHAPTER NO. 1
CHEMISTRY NOTES
CLASS: 9th
PREPARED AND
COMPOSED BY Romesa Farhaj
Q: What is chemistry?
Ans:
CHEMISTRY
The branch of science that deals with the properties, composition and
structure of matter is called chemistry.
chemistry also deals with the changes involved in a
matter.
it also deals with the principles governing the
changes which matter may undergo.
Q: Write 3 points on the importance of chemistry.
Ans:
IMPORTANCE OF CHEMISTRY
1. Chemistry enables us to design all sorts of materials.
2. Chemistry provides Drugs to fight diseases.
3. Chemistry provides pesticides to protect our health.
4. Chemistry provides Fertilizers to grow our crops.
5. Chemistry provides Fuels for transportation.
6. Chemistry provides Fibres to provide comfort and
variety in clothes.
7. Chemistry helps us to understand the nature of our
environment and about ourselves.
8. chemistry help us to understand the material world
from tiny atom to giant galaxies.
Q: Describe the historical development of chemistry.
Ans:
HISTORICAL DEVELOPMENT Of CHEMISTRY
Write any there of these
Historical development of chemistry consists of following three periods.
The Greek period
The Muslim period
The Modern Period
1. THE GREEK PERIOD
The Greek Philosophers like
Plato (347-428 BC),
Aristotle (322-384 BC),
Democritus (357-460 BC)
contributed a lot to the early development of chemistry. They introduced
the concept of elements, atoms and the chemical reactions.
They thought that all matter was derived from four elements.
Earth: Earth was dry and cold.
Fire: Fire was hot and dry
Air: Air was cold, wet and hot
Water: Water was cold, hot and wet
The ROMANS
They developed the chemical arts.
They improved metallurgical processes
introduced the enameling of poetry
and
They also developed little theorical knowledge
2. THE MUSLIM PERIOD
This period was from 600 to 1600 A.D. in the history
of chemistry and is known as the period of
"Alchemist". In the field of chemistry Muslims made
rich contribution and introduced scientific methods
and experimentations.
DISCOVERIES
LABORATORY EQUIPMENTS:
The Alchemists developed and used many laboratory equipment such
as:
Funnels
Beakers
Crucibles for melting
and fusion.
Retorts for distillation.
Balances for weighing
CHEMICALS:
They discovered
Various acids
Alcohols
Medicines
3. THE MODREN PERIOD
Q: write the contribution of Muslim scientists?
Ans:
JABIR IBNE HAIYAN (721 – 803)
He is generally known as the father of alchemy
CONTRIBUTION
• He invented experimental for the methods
preparations of Nitric Acid, Hydrochloric Acid and
white lead
• He also developed methods for the extraction of
metals
• He invented the methods for dying of clothes.
AL-RAZI (862 – 930 A.D.)
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He was a physician, alchemist, and philosopher.
CONTRIBUTION
• He prepared ethyl alcohol by the fermentation
process.
• He was the first to use opium as an anaesthesia.
• He divided the substances into living & non-living
origins.
AL-BERUNI (973 – 1048A.D)
He contributed a lot in physics, metaphysics, mathematics, geography
and history.
CONTRIBUTION
• He determined the densities of
different substances.
• He worked on precious stones &
metals.
Q: Write the contribution of scientists of the modern period.
ROBERT BOYLE (1625 – 1691 A.D)
• He is Known as the father of modern chemistry.
• He discovered relation between pressure and volume of the gas.
(known as Boyle’s Law)
J. BLACK (1728-1799 A.D)
• He made a study of carbon dioxide.
J. PRIESTLY (1733 – 1804 A.D)
• He discovered Oxygen, Sulphur dioxide and hydrogen chloride.
SCHEELE (1742-1786 A.D)
• He discovered chlorine gas
CAVENDISH (1731 – 1810 A.D)
• He discovered hydrogen
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LAVOISIOR (1743 – 1794 A.D)
• He discovered that oxygen constituted about one-fifth of air.
JOHN DALTON (1766 - 1844 A.D)
• He made a great stride in chemistry with his atomic theory of
matter. The idea of atoms and molecules became the established
fact
• He gave the concept of atomic weight.
JJ. BERZELLIUS (1779 - 1848 A.D)
• He introduced the idea of symbols, formulae and chemical
equation to make the study more systematic.
MENDELEEV (1824 – 1907 A.D)
• He discovered the periodic arrangement of the elements.
ARRHENIUS (1859 – 1927 A.D)
• The concept of acids and basis was presented by him.
FARADAY (1791 – 1867 A.D)
• He was put forward laws of electrolysis.
J. J. THOMSON (1856 – 1940 A.D)
• He discovered the charge of electron.
H. BECQUEREL (1852 - 1908 A.D)
• He worked on pitch blend (Uranium).
Madam Curie (1867 - 1934 A.D)
• She worked on radioactivity.
NEIL BOHR (1885 – 1962 A.D)
• He worked on structure of an atom.
E. RUTHERFORD (1891- 1937 A.D)
• He discovered the nucleus of atom
Q: define branches of chemistry.
Ans:
BRANCHES OF CHEMISTRY
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There are various branches of chemistry. The main branches of
chemistry are
1. Physical chemistry
2. Organic chemistry
3. Inorganic chemistry
4. Organic chemistry
5. Bio chemistry
6. Industrial and applied chemistry
7. Nuclear chemistry
8. Environmental chemistry
9. Polymeric chemistry
PHYSICAL CHEMISTRY
The branch of chemistry that deals with the laws and principals
governing the combination of atoms and molecules in chemical
reactions is known as physical chemistry.
ORGANIC CHEMISTRY
The branch of chemistry that deals with the carbon
compounds except some inorganic compounds of carbon is
called organic chemistry.
Or
The branch of chemistry in which we study about
hydrocarbons and their derivatives is called organic chemistry.
INORGANIC CHEMISTRY
The branch of chemistry that deals with the chemistry of
elements and their compounds, generally obtained from
non-living organisms i.e. minerals is known as inorganic
chemistry.
ANALYTICAL CHEMISTRY
The branch of chemistry that deals with the study of the
methods and techniques involved to determine the kind,
quality and quantity of various components in a given
substance is called analytical chemistry.
BIO CHEMISTRY
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The branch of chemistry that deals with the compounds of living
organisms is called bio-chemistry.
INDUSTRIAL CHEMISTRY
The branch of chemistry in which we deal with the study of
chemical processes involved in chemical industries for the
manufacture of synthetic products is known as industrial
chemistry.
NUCLEAR CHEMISTRY
The branch of chemistry that deals with the study of
changes occurring in the nuclei of atoms is known as
nuclear chemistry.
ENVIRONMENTAL CHEMISTRY
The branch of chemistry in which we deal with the
study of the chemical and biochemical phenomena
that occur in natural places is known as
environmental chemistry.
Or
the branch of chemistry that deals with the
occurrence, movements, and transformations of
chemicals in the environment is called
environmental chemistry.
POLYMERIC CHEMISTRY
The branch of chemistry that deals with the study of polymerization and
the products obtained through polymerization is known as polymeric
chemistry.
Q: Define scientific approach in chemistry.
Ans:
SCIENTIFIC APPROACH
The scientific approach in chemistry can be described through
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Observation, hypothesis, theory and law.
OBSERVATION
Observation is the basic tool for elaborating a
phenomenon but it may vary from person to person
according to his own skills
HYPOTHESIS
When the phenomenon is observed; a scientist
ponders over it and carries out relevant experiments
and arrives at a possible explanation for the nature
of the phenomenon. This explanation which is a trial
idea is known as hypothesis.
THEORY
When the hypothesis is supported by a large
amount of different types of observations and
experiments then it becomes a theory.
SCIENTIFIC LAW (Scientific Principal)
When a theory is tested again and again and is
found to fit all the facts and from which valid
predictions may be made is known as scientific law
or scientific principle.
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