INTRODUCTION TO CHEMISTRY

School:                  

Week: ONE                           Date:                                                                      Time:

Period:                                   Duration:                                                                               Average age of learners: 15YEARS

Subject:                 CHEMISTRY                                                                           Class: SS ONE

Topic:                                     INTRODUCTION TO CHEMISTRY

Sub topic:

Reference materials:

(1) ESSENTIAL CHEMISTRY, TONALD PUBLISHERS, I. O ODESINA

(2) NEW SCHOOL CHEMISTRY, AFRICAN FIRST PUBLISHERS, OSEI YAW ABABIO

(3) INTERNET

Instructional materials: Insecticides, grinding mill

Entry behavior: The students have been familiar with some application of chemistry

Behavioural objective: At the end of the lesson the students should be able to:

i.                     Define chemistry.

ii.                    State and explain branches of chemistry

iii.                  State the steps involved in scientific methods

Content

INTRODUCTION TO CHEMISTRY

The branch of science which deals with the composition and properties of matter, changes in matter and the laws or principles which govern these changes is called Chemistry.

BRANCHES OF CHEMISTRY

1.   Physical Chemistry

It is the branch of chemistry that deals with the law and the principles governing the combination of atoms and molecules in chemical reactions.

2.      Inorganic Chemistry

It is the branch of chemistry that deals with chemistry of elements and their compounds except carbon  , generally obtained from non-living organisms i.e. from minerals.

3.     Organic Chemistry

The branch of chemistry in which we study the compounds of carbon is called organic chemistry.

4.      Analytical Chemistry

It is 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

5.    Biochemistry

The study of chemical compounds present in living things is called biochemistry.

6.    Industrial Chemistry

The application of chemical knowledge in technology and industry and the preparation of industrial products are called industrial chemistry.

 7.   Nuclear Chemistry

It is the branch of chemistry that deals with the study of changes occurring in the nuclei of atoms, accompanied by the emission of invisible radiations.

8.  Environmental Chemistry

It is the branch of chemistry that deals with the study of the interaction of chemical materials and their effect on the environment of animals and plants.

9. Polymeric Chemistry

It is the branch of chemistry that deals specially with the study of polymerization and the products obtained through the process of polymerization such as plastics, synthetic fibers, paper etc.

STEPS INVOLVED IN GETTING INFORMATION IN THE SCIENTIFIC METHOD

Science is not only an integrated knowledge of physical and biological phenomena but also the methodology through which this knowledge is gathered. The process of scientific discoveries is a cyclic process.

In science the facts are gathered through observations and experiments and then theories or law are deduced. The scientific method include following four steps:

 1. Observation

2. Inference

3. Prediction

4. Experiment

1. Observation

The observations are made by the five senses of man. Men made equipments are also used for making observations. For example microscope is used for observing minute objects. Sensitive balance is used to determine the mass of a very light object. The capacity of man made instruments is also limited. But it can be improved by improving technology. Thus better and more reliable information are given to the scientists who produce better result. Information acquired through careful observations are called facts. These facts are foundation of scientific knowledge.

2. Inference

The facts gathered through observations are carefully arranged and properly classified. Correlating the knowledge thus acquired with previous knowledge, we try to think of a tentative solution to explain the observed phenomenon. The tentative solution is called hypothesis. The validity of this hypothesis is tested through the results obtained from experiments. The results are discussed by the scientists and the hypothesis is accepted or rejected. The accepted hypothesis then takes the form of theory. A theory when repeatedly gives the same results after experimentation and gives correct explanation of the scientific facts becomes a law or principle.

 A theory remains valid until contrary information are given on the basis of experimentation. Thus a hypothesis requires experimental support. But Avogadro’s hypothesis has been accepted as law without any experimental support.

3. Prediction

Facts, theories and laws which are deduced from observation can help in deducing more facts and phenomenon. This process is called prediction.

4. Experiment

An experiment is an integrated activity, which is performed under suitable conditions with specially designed instruments to get the required information. Such information is used to test the validity of the hypothesis. If a hypothesis is proved correct. It increases the reliability of known facts. If it is proved wrong, it still can give information which can be used to deduce other results.

CHEMISTRY AND SOCIETY

  Chemistry has played important role for well being of mankind in the form of food, clothing, shelter, medical treatment and chemical fertilizers, crops protected by insecticides, refined food and production of artificial fiber. Production of cement, iron bricks, glass, paint etc are all due to chemistry.

The hazards of chemistry are so vast that no aspect of human life has remained unaffected. The smoke coming from chimneys of chemial industries and from vehicles pollute the air. It is very dangerous to breath in that air. Similarly waste water from industry, pollute canals, rivers and has bad effect on land. Excessive chemical spray on plants also has bad effect.

APPLICATION OF CHEMISTRY

1.FOOD: Chemistry is used to increase food production by the use of fertilizer and insecticides, preservation and addition of essential nutrients to improve the quality of food.

2.CLOTHING: Textile fibres are produced by chemical research.

3.HOUSING: Cement, concretes, bricks, tiles and roofing sheets are produced by chemical processes.

4. MEDICINE: Chemical research is employed in the production of drugs and medicines.

5. TRANSPORTATION: Fuels and structural materials like alloys which are light, strong and heat resistance are produced by chemical processes.

ADVERSE EFFECTS OF CHEMISTRY

Environmental pollution

Drug abuse

CAREERS AVAILABLE IN CHEMISTRY

1.Teaching/Lecturing services

2.Health services

3.Food Technologists

4.Petroleum and petrochemical industries

5.Agriculture

6.Forestry

Introduction remarks: The teacher introduces the lesson

Presentation of teacher activity:

i.  The teacher defines chemistry.

ii. The teacher states and explains the branches of chemistry.

iii. The teacher explains the scientific methods.

iv. The teacher mentions area where chemistry is applicable.

Students’ activities:

i. The students chorus the branches of chemistry

ii. The students mention the scientific methods

iii. The students state the careers available in chemistry.

Evaluation: The teacher evaluates the lessons by asking the following questions:-

(i)                   Explain the word chemistry

(ii)                 Mention 4 areas in chemistry

(iii)                Briefly explain hypothesis and theory    

Assignment

Describe briefly how can chemistry affect the society adversely