SCIENCE LABORATORY

The laboratory is the centre to science education. It is in the laboratory that students learn to handle apparatus, think independently and to draw conclusions on the basis of experiments and observation. Laboratory work is an essential component of science education.  Scientific theories and practical work are two sides of a coin. These two aspects of science education should complement and supplement each other. Without experiments students cannot experience the reality of science. Practical works provides an activity which can be profitable and emotionally satisfying. The development of powers of observation, measurement and drawing inference are all dependent on laboratory work. Laboratory work helps to realise the process oriented objectives of science education.

NEED AND SIGNIFICANCE OF LABORATORY WORK IN SCIENCE EDUCATION

1.      The students can experience the reality of life. 

2.      Practical works provide an activity which can be profitable and emotionally satisfying.

3.      Helps in development of powers of observation, measurement and drawing inference etc. in learners.

4.      Laboratory work helps to realise the process orient objective of science laboratory.

5.      Making abstract science understanding concrete.

6.      Developments of scientific principle and concepts.

7.      Development of scientific skills, attitudes, interests and appreciation.

8.      Training in scientific method.

9.      Awakening the maintenance of curiosity in the environment.

 

ADMINISTRATION OF LABORATORY WORK

In order to make the practical work most effective, the teacher should always keep in mind the different aspects of laboratory work.

1.      Organising and conducting practical work.

Ø  There should be coordination of theoretical and practical work.

Ø  Experiments should be neither too difficult nor too easy.

Ø  The purpose of experiment should be made clear to pupils.

Ø  A faithful record of the experiments should be maintained by the pupils.

Ø  Pupils work should be keenly observed by the teacher.

Ø  Experiments should be graded according to age, intelligence, etc.

2.      Students should make to form appropriate groups.

3.      Preparation is required for individual and group work.

4.      Laboratory rules and discipline should be laid down.

5.      Instructions to pupils are to be specific and clear.

6.      Pupil’s records and observation book are to be properly maintained.

 

FEATURES OF A GOOD SCINCE LABORATORY

A good science laboratory should satisfy most of the following characteristics.

1.      It must be spacious- Linear bench space, storage space, permanent equipment space, demonstration space etc.

2.      It must quit conductive for hard work.

3.      Its plan must provide elements of flexibility for effective teacher demonstration as well as for individual and small group work.

4.      It must provide certain facilities for objectification.

5.      It must permit enough teacher supervision of the pupil’s work.

6.      It must have water, gas and electric points wherever they are needed.

7.      It must have ample storage facilities for equipment.

8.       It must have an emergency exit if it is not situated on the ground floor.

 

SELECTION AND PURCHASE OF APPARATUS AND CHEMICALS

While making a list of requirements the teacher should consider the following factors.

a.      Types of apparatus required.

b.      Quantity of each item.

c.       Choice of suppliers.

d.      Finance

e.      The number of subjects taught.

f.        The number of students and their level.

g.      The capacity of the laboratory.

h.      The knowledge and ability of the teacher.

 

PUECHASE OF APPARATUS AND CHEMICALS

After a list of selected items has been prepared, its copy is sent to three or four firms and quotations are obtained. One receipt of quotation, order should be placed to the firm which supplies the better equipment at cheaper rate. Local dealers should be preferred. If possible the teacher should go personally to the firm and get the things packed in his presence. On receiving the goods, the teacher should check with the list before signing their receipt. Any broken or damage items, incorrect quantities or wrong items supplied must be immediately informed to the dealer. The items should be entered in the school register on the same day.

REGISTERS MAINTAINED IN THE LABORATORY

Permanent stock register

In this register articles of metal, wood or permanent nature which are not liable to broken or consumed are to be entered. E.g. test tube rack, wooden stands, magnets, microscope, spectrometer etc.

Stock register of breakables

Articles of glassware like flask, beaker, funnel which are liable to broken are included in the register

Stock register of consumables

Chemicals and other fluids which are liable to be consumed are entered in third register.

Order register

This includes a record of orders send for purchase of apparatus and chemicals to different firms.

Requirement register

In the requirement register, the teacher should not down the requirements which he remembers at the time and which he feels necessary during the experiment.

LABORATORY RULES AND DISCIPLINES

Laboratory safety is positive understanding which the science teacher is expected to take up at the time of engaging any activity in the laboratory, in presence of his students. The following are the some suggestions for the maintenance of discipline in the laboratory.

1.      No pupil should allowed to enter the laboratory in the absence of the teacher.

2.      Pupil should perform only those experiments assigned by the teacher.

3.      Every students should have a place assigned to him for his experiment.

4.      Equipment/chemical should be used until proper instructions are received from the teacher.

5.      Specimens, solid waste, broken glass, burnt up match sticks and other laboratory wastes should be deposited in waste boxes.

6.      Reagent bottles should be returned to the shelf immediately after use and these should not be misplaced.

7.      Any breakage of apparatus or accidents or injury must be reported to the teacher.

8.      Playing with the apparatus should be prohibited.

9.      The apparatus should be disconnected, washed if necessary and replaced in their proper places.

10.  Consider the safety of fellow students. A scientific atmosphere should be kept up in the laboratory

ACCIDENTS AND FIRST AIDS IN THE LABORATORY

The science teachers have a legal and moral responsibility to see that the pupils are safe from the dangers of the laboratory. Pupils must be aware of the hazards involved in any experiments they do. Pupils must be made to understand the laboratory rules and follow them.

The purpose of the first aid is to make patient secure and comfortable and to prevent deterioration in his condition, until professional medical assistance is available. The strategies of first aid-diagnosis, treatment and transport

1.      FIRE

a)   If a person’s cloth catch fire, to be wrapped tightly in a fire proof blanket.

b)  If some inflammable substance get ignited in a beaker the fire can be extinguished        and prevent from spreading by pressing a sheet of asbestos over the mouth of the vessel.

c)  Small fire due to oil, phosphorous, sodium etc. can often be put by smothering      them with large quantity of sand.

d)  If the fire is due to gas or electricity, the source of supply or the main connection should be cut off.

   

 2. BURNS

             Burn is caused by dry heat such as hot iron, hot glass rode, fire, by some acid or alkali,phosphorous or sodium or potassium.

a)     Burn from fire

            Burnol paste is smoothly applied and allowed to remain on the burnt part. If necessary a loose bandage to be tied.

b)     Acid burns

            Acid burns must be immediately washed with large quantity of water and then sodium bicarbonate solution.

c)      Alkali burns

            Alkali burns must be washed with 1% solution of acetic acid or lemon juice.

 

d)     Phosphorous burns

            Phosphorous burns must be immersed in water and all the traces of the substance washed away. The part should be treated with dil. AgNO₃.

3. EYE BURNS

Acid in eye: the eye should be open and closed under water. It should be then washed with water or 1% solution of sodium bicarbonate.

Alkali in eye: The eye should be thoroughly rinsed with water and then with 1% solution of boric acid.

Solid in eye: The eyelid may be turned back gently over a match stick. Any foreign matter may be removed with fine camel brush dipped in glycerine.

4. POISONING

a) For corrosive substances

            The patient should give white egg or milk, and rice water or barley water. He should not be encouraged to vomit or should not give any purgative.in the case of acids much water followed by lime water or milk. In case of alkalies much water followed by 1% acetic acid or lemon juice.

b) For non-corrosive poisons

            A spoonful of table salt or a tea spoon full of mustard oil in a tumbler of water should be should be given. This will encourage vomiting. The white of egg or rice water may be also given.

5. INHALATION OF GASES

            In the case of gas poisoning, the patient should at once be taken into the fresh air and his clothes should be loosen.

By chlorine or Br₂               :           Inhale ammonia or alcohol vapour.

By nitrous fumes         :          Inhale open fresh air.

By chloroform                          :          Inhale plenty of fresh air.

6. CUTS

            When there is a major cut n any part of the body and some artery or vein is injured, it is essential to stop the bleeding. In order to stop bleeding, it is necessary to understand whether a vein or artery has been cut. If it is continues blood flow, then the vein has been injured. For that in direct pressure should be applied by tying a narrow bandage on the distal of the wound but care should be taken the pressure applied should be taken the pressure should only collapse the vein and not the artery. If the blood spurts then artery has been cut, pressure on the proximal side of the wound or in extreme cases the use of tourniquet may be necessary to control it.