Element Properties: 9-15 atomic number


Atomic symbol: F

Atomic weight: 18.9984032

Atomic number: 9

Electron configuration: 2-7

Oxidation states: -1

State of matter: gas Non-metal

Discovered in 1886 by Henri Moissan

Boils at -188°C, freezes at -220°C


Fluorine is the most active member of the halogen family, and produces the most stable compounds. It is very poisonous because of its great activity. It is so active that it is not found free in nature, only in a combined state, and is very abundant. It occurs as either the mineral fluorine, or the mineral cryolite. Freon, the refrigerant, contains fluorine. Cryolite, or sodium aluminum fluoride, is an important flux in the electrolytic production of aluminum metal. Compounds of fluorine and carbon are important because of their heat and fire resistance. Fluorine is found in tap water and toothpaste, which had beneficial effects on teeth. Other fluorine compounds are used as insecticides and wood preservatives.


Atomic symbol: Ne

Atomic weight: 20.1797

Atomic number: 10

Electron configuration: 2-8

Oxidation states: 0

State of matter: gas

Noble gas

Discovered in 1898 by Sir William Ramsay and Morris W. Travers

Boils at -246°C, melts at -248.7°C


Neon is obtained from the fractional distillation of liquid air. Its main use is in neon signs. Neon signs are made of helium, neon, argon, or mercury at different pressures. These are then put into different colored glass, which gives off different colors.


Atomic symbol: Na

Atomic weight: 22.989768

Atomic number: 11

Electron configuration: 2-8-1

Oxidation states: +1

State of matter: solid

Light metal

Discovered in 1807 by Sir Humphry Davy

Boils at 883°C, melts at 97.8°C


Sodium is a light silvery-white metal, lustrous when freshly cut, but tarnishes when exposed to air, becoming dull and gray. It is too active to be found in nature, and reacts vigorously with water, exploding upon contact with a large chunk. Most metallic sodium is used in the manufacture of tetraethyl lead, an alternative for gas. Other uses are the manufacture of a variety of organic chemicals, and the reduction of titanium metal. It is also a good electron source for photoelectric cells and cyclotrons.


Atomic symbol: Mg

Atomic weight: 24.3050

Atomic number: 12

Electron configuration: 2-8-2

Oxidation states: +2

State of matter: solid

Light metal

Discovered in 1808 by Sir Humphry Davy

Boils at 1090°C, melts at 649°C


Magnesium is one of the most common elements in the earth’s crust. It burns with a brilliant white color, and slowly oxidizes in moist air. It is an important structural metal, often used in either pure or alloyed form with aluminum in the construction of aircraft. It is also frequently used in the production of objects requiring a light weight. Powdered magnesium is sometimes used in place of aluminum in the thermite reaction.


Atomic symbol: Al

Atomic weight: 26.981539

Atomic number: 13

Electron configuration: 2-8-3

Oxidation states: +3

State of matter: solid

Heavy metal: low melting

Discovered in 1827 by Friedrich Wöhler

Boils at 2467°C, melts at 660°C


Aluminum is a white, malleable, ductile metal, with a somewhat bluish tint. It occurs in a variety of silicate rocks, mainly mica and feldspar. These rocks disintegrate by a process called weathering, in which moisture and carbon dioxide form clay, and ultimately aluminum oxide. Weathering also forms the principal aluminum ore, bauxite. Aluminum also occurs as cryolite. Because of its light weight, resistance to corrosion, and tensile strength, it is excellent for the construction of the structure of a building. Because it can easily be rolled into sheets, much is used for aluminum foil. Aluminum powder is sometimes used in some types of paint.


Atomic symbol: Si

Atomic weight: 28.0855

Atomic number: 14

Electron configuration: 2-8-14

Oxidation states: +2, ±4

State of matter: solid


Discovered in 1818 by Jöns Jacob Berzelius

Boils at 2355°C, melts at 1415°C


Silicon is black-gray and a poor conductor of electricity. It is never found free always combined with oxygen. The two principal combinations of silicon are silicon dioxide, which is found as flint, quartz, sand, sandstone, agate and amethyst and silicate rocks. These rocks range from garnet to asbestos.


Atomic symbol: P

Atomic weight: 30.973762

Atomic number: 15

Electron configuration: 2-8-5

Oxidation states: ±3, +5

State of matter: solid


Discovered in 1669 by Hennig Brand

Boils at 280°C, melts at 44.1°C


Phosphorus exists in three main allotropic forms—white, black, and red. It is too active to be found in nature, and most of it is combined with oxygen. Its principal ores are phosphorite and apatite. White phosphorous is waxy, soft and translucent, and becomes brittle at 5.5°C. It is crystalline, insoluble in water, and extremely poisonous.