Chemistry

THE ATMOSPHERE The atmosphere is made up of air. Air is a mixture of colourless, odourless gases which is felt as wind (air in motion). All living things breathe in… Read More »THE ATMOSPHERE

In a school laboratory: An acid may be defined as a substance that turns litmus red. A base may be defined as a substance that turns litmus blue. Litmus is… Read More »INTRODUCTION TO ACIDS, BASES AND INDICATORS

PHYSICAL PROPERTIES OF ACIDS Acids have a characteristic sour taste Most acids are colourless liquids Mineral acids are odourless. Organic acids have characteristic smell All acids have pH less than… Read More »PROPERTIES OF ACIDS

A physical/temporary change is one which no new substance is formed and is reversible back to original. A chemical/permanent change is one which a new substance is formed and is… Read More »PHYSICAL/TEMPORARY AND CHEMICAL CHANGES

Mixtures can be separated from applying the following methods: DECANTATION Sediments can be separated from a liquid by pouring out the liquid. This process is called decantation. Experiment Put some… Read More »METHODS OF SEPARATING MIXTURES

Substances are either pure or impure. A pure substance is one which contains only one substance. An impure substance is one which contains two or more substances. A pure substance… Read More »CLASSIFICATION OF SUBSTANCES

Chemistry is used in the following: 1. Washing/cleaning with soap: Washing/cleaning is a chemical process that involves interaction of water, soap and dirt so as to remove the dirt from… Read More »THE ROLE OF CHEMISTRY IN SOCIETY

Chemistry is studied mainly in a science room called a school chemistry laboratory. The room is better ventilated than normal classroom. It has electricity, gas and water taps. A school… Read More »CHEMISTRY LABORATORY AND APPARATUS

Water is an important item in our universe. We need water for transport (lakes and oceans), Generation of power, (hydroelectricity), drinking industrial processes, manufacturing and cooling among others. Very little… Read More »WATER ON EARTH

Chemistry is a branch of Science. Science is basically the study of living and non-living things. The branch of science that study living things is called Biology. The branch of… Read More »INTRODUCTION TO CHEMISTRY

Oxygen (O2) is an active, life-sustaining component of the atmosphere; making up 20% by volume of the air we breathe. It is colorless, odorless and tasteless. Oxygen is the most… Read More »OXYGEN (O2) PROPERTIES AND USES

Corrosion The eating up of metals by the action of air and moisture on their surface is called corrosion. The corrosion of iron is called rusting. While other metals are… Read More »RUSTING OF IRON

Hydrogen is the simplest element. It is the first element in the periodic table, and it is placed in Group I of the periodic table.   Hydrogen Occurrence Hydrogen is… Read More »WATER AND HYDROGEN

Red cabbage juice solution works well instead of universal indicator solution.   Making Cabbage Indicator Acid base indicators are chemicals that change colour in the presence of different pH levels.… Read More »INDICATORS

A compound is a pure substance formed by chemically combining at least two different elements. Compounds are two or more different elements combined. Their atoms have been joined or bonded… Read More »COMPOUNDS AND FORMULA

Sometimes we need pure substances as opposed to impure ones. You can imagine a mixture of sand and table salt and imagine how much use you would have for it.… Read More »SEPARATION OF MIXTURES