Warning Signs

Warning signs are signs on the containers of chemicals as warnings about the danger of the contained chemical.


There are six warning signs.

Explosives
These are substances can explode. An explosion is a forceful rapid reaction which involves the throwing off 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.
Oxidising agent makes a small fire to become bigger. Heating a mixture of an organic material with an oxidising agent may cause explosion. Eg; heating potassium permanganate with saw dust.




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 as well can corrode floors and desktops.
If by accident, a corrosive substance comes into contact with your skin, go to the sink and wash your skin with a lot of water. Examples; Concentrated mineral acids like HCl and HNO3 II. 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 - these substances may cause illness or endanger your health. They won't kill instantly but they are lethal. Irritating substances- cause pain in eyes or on your skin and can endanger your health if you are in contact with them doe too long.
They should be handled according to the stipulated instructions.





Scientific Investigation.

Scientific investigation refers to the step-by-step procedures and methods employed in carrying out a scientific research.

Basic Principles of Science Investigation

There are six different scientific step:

1. Identification of a problem: This is the first step where a problem is recognized. It provides explanations to the day-to-day questions which we come across in our lives Eg; It is observed that despite adequate feeding, vaccination, treatment and spacious rooms, hens lay fewer eggs each day. What is the cause of the fewer number of eggs?

2. Formulation of hypothesis: Hypothesis is an intelligent guess or a tentative explanation for the observation made. Using the example of a few eggs laid by hens per day the hypothesis could be; a smaller number of eggs are laid because of unusual high temperature in the room. In order to prove this hypothesis, an experiment have to be carried out.

3. Experimentation: The experiment involves a series of investigations intended to discover relationships or certain facts that may lead to the acceptance, rejection or modification of a hypothesis. The first step in experiment is to construct a plan of investigation.

4. Observation and data recording: After setting up the experiment, a researcher makes careful observation using their sense organs and records all events that considers relevant.

5. Interpretation of data: Once a researcher has collected data, he should try to explain the meaning of the experiment. This is an attempt to interpret the data. The data may be presented in a form of a table, bar chart, histogram or even graph.

6. Conclusion: This is either confirmation or rejection of hypothesis.


Theory.
A Theory is a set scientific assumptions consistent with one another and supported by evidence but not fully proved (is a hypothesis with more evidence).

Fact is a proved theory supported by evidence

Hypothesis →Theory →Fact.