( CHEMISTRY CHAPTER 1 )

NAME : SITI NOREZAN BT. SAMSUDDIN

CLASS : 4 BESTARI

YEAR : 2010

CHEMISTRY AND ITS IMPORTANCE

What is chemistry ?

The word ‘chemistry’ comes from the earlier study alchemy, which is an art of transforming common metals such as lead into precious metals, such as gold and silver. Although no one ever succeded in doing so, substance like mercury, sulphur, antimony and phosphorus, and processes like purification and distillation were discovered.

Anyway, chemistry is defined as the study of the composition, structure, properties, and interactions of matter.

Common chemicals used in daily life

Matter is anything that occupies space and has mass. All matter is considered as chemical.

Common chemicals Uses of common chemicals

Baking powder(sodium bicarbonate)

Raises the dough for bread making

Lime (calcium oxide) Reduces the acidity of soil

Marbles tiles(calcium carbonate)

Flooring in our house

Nail varnish removal(propanone)

Removes nail varnish

PVC(Polyvinly chloride) Pipe, electrical insulators

Soap(sodium stearate) Soap used in bathing

Table salt(sodium chloride) Gives salty taste

Vinegar(dilute ethanoic acid)Preserves food

*Example of some common chemicals and their uses

Careers that use chemistry

Many professions require the knowledge chemistry. Chemist is among the careers that relies 100% on chemistry knowledge. Chemist do analysis works in laboratories and carry out researches to produce new materials to improve our quality of life.

Field

Career

Scope of job

Agriculture Aquaculturist >Study the ways of growing aquatic organism

Horticulturist >Study or practice the ways of growing fruits, flowers and vegetables.

Medicinal Doctor >Treat people who are ill and injured

Pharmacist >Prescribe medicines in a shop or hospital or create new drugs to cure diseases

Veterinarian >Treat animals which are ill or injured

Industry Nutritionist >Study the nutritional value of food

Food technologist >Study the correct mixture of flavours, antioxidants, colourings, stabilizers, thickners and preservatives

Biotechnologist >Study the use of living cells and bacteria in industrial and scientific process

Education Lecturer >Teach chemistry related topics in

universities, colleges and matriculation

Teacher >Teach chemistry in school

Geologist >Study the chemical elements present in the earth samples

Hazardous materials expert

>Have information on thousands of types of chemicals and how they react with people, fire and air>Help the fire fighters to evacuate people, tell them how to contain the unidentified chemicals

*Example of careers and their scope of jobs

Chemical-based industries in Malaysia and their contribution

Malaysia has great number of chemical-based industries. Petroleum, natural gas,

rubber and oil palm are among the important industries in Malaysia.

Chemical-based industries

Product

Petroleum Liquefied natural gas, gasoline, kerosene, bitumen

Rubber Rubber glove, footwear, tyre, condom

Palm oil Margarine, cooking oil, raw material for manufacturing soap, detergent, cosmetic and lubricant

Petrochemical Plastic, raincoat, pail, and other plastic ware

Inorganic chemical Chlorine, caustic soda, bleaching agent

Paint Paint, varnish, dye

Agricultural chemical and fertiliser

Fertiliser, pesticide

Soap and detergent Soap, detergent

Cosmetic Cosmetic

Pharmaceutical Drugs used in medicine

Chemical-based industries are very important in

Producing new materials to improve our quality of life.

Providing job opportunities.

Earning foreign exchange at which it contributes to the economy of the country.

Scientific method

The scientific method involves the following steps :

Making an observation

Gather information of a phenomenon using five senses

Making an inference

Make a tentative explanation or smart guess based on the observation

Identifying the problem

Formulate a question based on the inference

Making a hypothesis

Make a general statement to related a manipulated variable and a responding variable to answer the question

Identifying the variables

Identifying

Manipulated variable: a factor which is purposely changed during the experiment

Responding variable: a factor that responds to the change of manipulated variable

Constant variable: factors which are kept same throughout the experiment

Controlling the variables

Decided how to change the manipulated variable, how to measure the responding variable and way to keep the constant variable

Planning an experiment

Determine the apparatus and materials used, produce of experiment and ways to collect, analyse and interpret data

Collecting data

Record the results accurately

Interpreting data

Analyse the results and present them in the form of table, graph or calculation

Making a conclusion

Draw a general statement about the outcome of the experiment

Writing a report

Write a report that enables the scientist to communicate with other scientist

A new hypothesis is construct if the hypothesis is rejected

Hypothesis that is accepted well become a theory

Scientific Attitudes and Noble Values

The success of science has more to do with common to scientists than with a particular method.

A good scientist needs to have an enquiring mind, and should question everything he or she is told.

When carrying out an experiment, a scientist should have the interest, curiosity, objectivity, flexibility, openness and creativity.

A scientist should be honest in recording observations and measurements without altering the results.

Only with positive attitudes then you will be able to appreciate the chemistry knowledge.