Introduction To Laboratory Practice

 


A Laboratory is a room or a building designed specifically for carrying out experiments.

Rules in a Physics Laboratory

While working in the lab, individuals are advised to adhere to specific lab rules to ensure their safety, that of other people working in the lab and the safety of the apparatus and chemicals stored in the lab.

 

Rules in a Physics laboratory:

1. You should only enter the lab in the presence of a lab attendant.

2. Keep all exits and entrances to and from the lab clear of obstructions.

3. Do not eat or drink in the lab.

4. Solid objects should not be thrown into the sink or water ways.

5. Do not use any lab container for drinking or storing food.

6. Make sure that you wash your hands with soap before you leave the lab.

7. The cover or stopper of a particular chemical must be replaced immediately after use.

8. After experiments, clean your bench and leave it dry and well arranged.

9. Never quarrel or fight in the lab.

10. Never use ungloved hands to hold hot objects

 

Safety measures in a Physics Laboratory:

1. All experiments which produce poisonous fumes must be conducted in the fume chamber.

2. Lab floors should not be polished to avoid slipperiness.

3. A Lab should have large windows, and doors should be opened outwards.

4. Ensure that the fire extinguisher is fixed in an appropriate place, ready to be accessed in case of fire.

5. In a multi storey building, a Physics lab should be in the lowest floor.

 

Using First Aid Kit

First Aid is the immediate care given to accident victims or an injured person before he/she is taken to a hospital for further medical treatment. It reduces pain and helps to bring hope and encouragement to accident victims.

A First Aid Kit is a collection of medical supplies (such as bandages, plasters, pain killers, antiseptics) and equipment that is used to give medical treatment to a sick person or an accident victim, before taking the person to a hospital.


Contents of a first aid kit and their uses



Warning Signs in Chemical Containers:

Warning signs are signs found on Chemical containers, indicating the danger of the contained chemical. There are six warning signs.

Explosives

These are substances that can explode. An explosion is a forceful, rapid reaction which involves the throwing of particles at high speeds.



The sign means that it is dangerous to keep explosives in glass containers.

Oxidant

This is a chemical/substance that helps a burning substance to burn faster.

An oxidising agent makes a small fire become bigger. Heating a mixture of an organic material with an oxidising agent may cause an explosion. E.g. heating potassium permanganate with sawdust.

 

Flammable



These substances catch fire easily. They should not be kept near open flames. If heated, an electric heater should be used.


Corrosive

These substances burn skin and can also corrode floors and desktops.



If by accident, a corrosive substance comes into contact with your skin, immediately go to a sink and wash your skin with a lot of water. Examples of corrosive substances include Concentrated mineral acids like HCl and HNO3 II, and Concentrated alkalis like NaOH and KOH

 

Toxic

These are very poisonous and can cause death immediately after use or after a few days. They should not be allowed to come into contact with you.


If you come into contact with such a chemical accidentally, wash it away with a lot of water.


Harmful/irritant

Harmful Chemicals are substances that may cause illness or endanger your health. They won’t kill instantly, but they are lethal. Irritating substances cause pain in the eyes or on your skin and can endanger your health if you are in contact with them for too long.

They should be handled according to the stipulated instructions.


Warning Signs in Daily Life

Use warning signs in daily life

Warning signs help us to know the possible danger that is near us so that we can take precautions before it is too late. For example, in hospitals, there are doors labelled with radioactive symbols to warn the passers of the harmful radiation from X-ray machines. These symbols can also be seen in mining areas.

 

Boxes containing materials like glasses, which can easily break, are labelled with a fragile warning sign to remind anyone who carries the box to be careful. Warning signs can be found on several materials to ensure that safety is observed.

 

Activity 1

List and draw any five warning signs in your environment and state their uses in your daily life.

 

The Concept of Scientific Investigation

Explain the concept of scientific investigation

Scientific investigation refers to the step-by-step procedures and methods used in carrying out a scientific investigation. It involves a deep study into the problem, its causes and obtaining the solution through experiments and analysis of the results obtained.

Scientific investigation is the way through which scientists can apply research skills and techniques to examine a problem and finally come to a proper conclusion.

 

Steps of Scientific Investigation

Identify the steps of scientific investigation

There are 8 common steps to follow when doing a scientific investigation.

1. Identification of a problem - This is the first step where a problem is recognised or observed. For example, a scientist may observe that every day at noon, their bicycle tire bursts.

2. Asking questions – At this stage, a scientist asks self-questions about the observed problems. For example, does the hot weather at noon cause the observed tire bursts?

3. Hypothesis formulation – This is the stage where a scientist guesses the possible causes of the observed problem. The scientist tries to guess intelligent answers to the questions asked in the second step, for example, the bursting of the tire is mainly caused by the hot temperature at noon. The hypothesis can be true or false.

4. Experimentation – At this stage, the hypothesis is being tested scientifically. An experiment is a test conducted in a controlled condition or environment, such as in a laboratory. The aim of the experiment is to obtain scientific answers or data about the observed problem. Data is a set of facts, values or details which can be translated to give a meaning.

5. Collection of data and analysis – During experimentation, results or data obtained are collected and recorded in a good and systematic manner. One good way of recording data is by using tables (tabular form).

6. Data interpretation – At this stage, the data recorded are related to one another to obtain the relationship between them. For example, it may be found that as the temperature of the surroundings increases the size (volume) of the tire becomes large.

7. Presentation of data – This is when the data or information obtained is put in a form that can be well understood. In this stage, mathematical formula, graphs and diagrams can be used to explain the results.

8. Conclusion – This is when a scientist comes out with a statement or summary to agree or disagree with the hypothesis according to the results obtained from the experiment. The scientist provides the possible solution to the problem observed on the first step. For example, the bursting of a tire at noon is caused by enormous expansion of air inside the tire brought by rise in temperature.

 

 

Post a Comment

Previous Post Next Post