Category Chemistry Lesson Notes For SS1 – SS3

Ionic (Electrovalent) Bonding Noble gases like neon or argon have eight electrons in their outer shells (or two in the case of helium). These noble gas structures are thought of as being in some way a “desirable” thing for an…

Characteristics of Periods The first period starts with hydrogen (H) and ends with helium (He). It has just two elements H (Z=1) and He (Z = 2). H has one electron in the first-shell. He has 2 electrons in the…

In this group, we have Helium (He), Neon (Ne), Argon (Ar), Krypton (Kr), Xenon (Xe) and Radon (Rn). The electronic configuration will show that these atoms all have a complete outer shell of electrons and are not interested in reacting…

The halogens are all in group 7 on the right of the periodic table. This group consists of elements like Fluorine (F), Chlorine (Cl), Bromine (Br), Iodine (I), Astatine (At). The Halogens are typical non-metals and form the 7th Group…

Going down Group 2: There are more filled energy levels between the nucleus and the outer electrons, therefore the outer electrons are more shielded from the attraction of the nucleus So the electrons in the outer energy levels are further…

As you go down the group from one element down to the next the atomic radius gets bigger due to an extra filled electron shell. The outer electron is further and further from the nucleus and is also shielded by…

Dmitri Mendeleev is credited as being the Father of the modern periodic table. In 1869 he arranged the 50 or so known elements in order of atomic number, Z, putting elements with similar properties in the same vertical group, and…

It is interesting to note that atoms of a given atomic number can have different number of neutrons. Atoms of elements having the same atomic number with different mass numbers are called isotopes Some examples are listed below: It has…

When Hydrogen is passed through unsaturated compounds in presence of Nickel catalyst and about 150oC, they become saturated. Most vegetable oil are unsaturated liquids at room temperature. They become saturated and hard through hydrogenation. Hydrogen is the lightest known gas.…

The Structure of The Atom When scientists started exploring matter, they realized that matter can be divided into smaller and still smaller particles. They called the smallest particle an ‘atom’. The name ‘atom’ was derived from the Greek word ‘atoms’,…

Physical properties When mixed with air it has a characteristic pungent choking smell Chemical properties. Burning III. Impure(air mixed with) hydrogen burns with an explosion. Small amount/volume of air mixed with hydrogen in a test tube produce a small explosion…

Occurrence Hydrogen does not occur free in nature. It occurs as Water and in Petroleum. School laboratory Preparation Procedure Put Zinc granules in a round/flat/conical flask. Add dilute sulphuric(VI) /Hydrochloric acid. Add about 3cm3 of copper(II)sulphate(VI) solution. Collect the gas…

The higher the metal in the reactivity series the more reactive the metal with water. The following experiments show the reaction of metals with cold water and water vapour Reaction of Sodium/Potassium with Cold Water: Procedure Put about 500cm3 of water…

Water pollution take place when undesirable substances are added into the water. Sources of water pollution include: Water pollution can be reduced by:

Pure water is a colourless, odourless, tasteless, neutral liquid. Pure water does not exist in nature but naturally in varying degree of purity. The main sources of water include rain, springs, borehole, lakes, seas and oceans: Water is generally used…

Metals compete for combined Oxygen. A metal/element with higher affinity for oxygen removes Oxygen from a metal lower in the reactivity series/less affinity for Oxygen. When a metal/element gains/acquire Oxygen, the process is called Oxidation. When metal/element donate/lose Oxygen, the…

The following experiments show the reaction of non-metals with Oxygen and air. Burning Carbon Procedure (a) Using a pair of tongs hold a dry piece of charcoal on a Bunsen flame. Observe. Place the products in a beaker containing about…

Oxygen is put in cylinders for use where natural supply is not sufficiently enough. This is mainly in: A mixture of oxygen and some other gases produces a flame that is very hot. Chemical properties of Oxygen Oxygen is…

The following experiments show the reaction of metals with Oxygen and air. Burning Magnesium Procedure (a) Cut a 2cm length piece of magnesium ribbon. Using a pair of tongs introduce it to a Bunsen flame. Remove it when it catches…

a) Occurrence. b) School laboratory preparation Oxygen was first prepared in 1772 by Karl Scheele and later in 1774 by Joseph Priestly. It was Antony Lavoisier who gave it the name “Oxygen” Procedure Method 1: Using Hydrogen peroxide Half fill a…