In chemistry, the main group is the group of elements (sometimes called the representative elements) whose lightest members are represented by helium, lithium, beryllium, boron, carbon, nitrogen, oxygen, and fluorine as arranged in the Periodic Table of the elements.

Helium (He): Helium holds the lowest melting and boiling points among all the other elements. The nuclear fusion of hydrogen in stars generates helium in a significant amount.

Chemical properties are simply the characteristics that define how the element reacts with other substances or changes from one to another substance.

Lithium (Li): Lithium is the first member of the alkali metal family. The Periodic Table is a chart that shows how chemical elements are related to one another. The alkali metals include sodium, potassium, rubidium, cesium, and francium.

Physical properties of lithium: Lithium is a very soft, silvery metal. It has a melting point of 180.54°C (356.97°F) and a boiling point of about 1,335°C (2,435°F). Its density is 0.534 grams per cubic centimeter.

Chemical properties of lithium: Lithium is an active element, but not as active as the other alkali metals. Under the proper conditions, the element also combines with sulfur, hydrogen, nitrogen, and the halogens.

Beryllium (Be): Beryllium is a chemical element with atomic number 4, represented by the chemical symbol ‘Be’. It is a toxic, bivalent element having a steel gray appearance.

Beryllium belongs to the alkaline earth metal category, s-block and period 2 of the Periodic Table.

Beryllium is light, silver-gray, relatively soft metal that is strong but brittle. Beryllium has the highest melting point (1278^oC) of the light metals.

Beryllium has high thermal conductivity and is non-magnetic.

Boron (B)

Physical Properties of Boron:

• Pure boron is a dark amorphous powder.
• Boron atoms can bond in a number of different types of crystal networks called allotropes.
• It has a low density of 2.37 grams per cubic centimeters.
• Boron salts emit a green color when introduced in Bunsen flame.

Chemical Properties of Boron:

• Boron in its crystalline form is very unreactive. Amorphous boron is reactive.
• Boron tends to make covalent bonds rather than ionic bonds.
• Boron is not reactive when comes in contact with acids and alkalis at moderate temperatures.
• It reacts with metals to form borides

Carbon (C)

Carbon is a chemical element that is non-metallic. Its symbol is ‘C’. Its atomic number is 6. It belongs to group 14 in the Periodic Table. Carbon is mainly found in coal deposits; however, the carbon obtained from coal deposits must be processed for its commercial use.

Graphite: It is black in color and opaque. It is a good conductor of electricity. It is a very good lubricant and the softest material known and greasy to touch.

Diamond: It occurs naturally in a free state. It is a very stable allotrope of carbon made up of four covalent bonds around one carbon atom.

Chemical properties of oxygen: Oxygen’s most important chemical property is that it supports combustion. That is, it helps other objects to burn. The combustion (burning) of charcoal is an example. Charcoal is nearly pure carbon (C).

Oxygen also combines with elements at room temperature. Rusting is an example. Rusting is a process by which a metal combines with oxygen.

Oxygen itself does not burn. A lighted match in a container of pure oxygen burns much brighter, but the oxygen does not catch fire.

Chemical properties of fluorine

Fluorine is the most reactive element. It combines easily with every other element except helium, neon, and argon. It reacts with most compounds, often violently. For example, when mixed with water, it reacts explosively.