HYDROGEN
Atomic symbol: H
Atomic weight: 1.00794
Atomic number: 1
Electron configuration: 1
Oxidation states: ±1
State of matter: gas
Alkali metal
Discovered in 1790 by Henry Cavendish
Boils at-252.8°C, melts at-259.14°C
Notes:
Hydrogen is a colorless, odorless, tasteless gas that can be flammable or explosive when mixed with air, oxygen, and chlorine. Hydrogen is not very reactive at room temperature, but at higher temperatures it burns vigorously and often explosively in air or oxygen to form water. In the presence of a catalyst and under pressure, hydrogen will combine with vegetable oils to form solid fats used as shortening, in a process known as hydrogenation. This process is extensively used in the refining of oil products to increase the yields of gasoline. It is also commonly used to make ammonia and many other chemical substances. Other uses are to fuel rockets and in fuel cells to generate electricity.
HELIUM
Atomic symbol: He
Atomic weight: 4.002602
Atomic number: 2
Electron configuration: 2
Oxidation states: 0
State of matter: gas
Noble gas element
Discovered in 1895 by Sir William Ramsay
Boils at 268.9°C, melts at 272.2°C
Notes:
Helium is a colorless, odorless, tasteless, nonflammable, monatomic inert gas. It is obtained from natural gas deposits by liquefying all other constituents and collecting the helium. The percentage obtained from these deposits may range from 1% to 2%. It is sometimes used to fill balloons and airships, along with many other scientific applications.
LITHIUM
Atomic symbol: Li
Atomic weight: 6.941
Atomic number: 3
Electron configuration: 2-1
Oxidation states: +1
State of matter: solid
Light metal
Discovered in 1817 by Johan August Arfwedson
Boils at 1342°C, melts at 180.5°C
Notes:
Lithium is a silvery white metal that turns yellow when exposed to moist air. When heated sufficiently, it emits light radiation that is red in color. Lithium is a good electron source in photoelectric cells and cyclotrons.
Atomic symbol: Be
Atomic weight: 9.012182
Atomic number: 4
Electron configuration: 2-2
Oxidation states: +2
State of matter: solid
Light metal
Discovered in 1797 by Louis-Nicolas Vauquilin
Boils at 2970°C, melts at 1278°C
Notes:
Beryllium is very rare, its pricipale ore is beryl, a complex aluminosilicate. When beryl has traces of chromium impurities, it is emerald. When beryl contains traces of iron, its aquamarine. Beryllium does not occur free in nature, and is primarily used in alloys—especially copper to form non- sparking tools.
Atomic symbol: B
Atomic weight: 10.811
Atomic number: 5
Electron configuration: 2-3
Oxidation states: +3
State of matter: solid
Non-metal
Discovered in 1808 by Joseph Louis Gay-Lussac and Louis-Jacques Thènard
Boils at 2550°C, melts at 2300°C
Notes:
Boron is relatively rare, and always found combined with oxygen in borates. It is extremely hard and brittle, and is found in two allotropic forms—crystalline and amorphous. Boron is used in flares to give off a green color, as an igniter in rockets, as filaments in aerospace structures, and in silicon semiconductors to improve conductivity. It is also used in nuclear chemistry as a neutron absorber and typically to harden other metals.
Atomic symbol: C
Atomic weight: 12.0107
Atomic number: 6
Electron configuration: 2-4
Oxidation states: +2, ±4
State of matter: solid
Non-metal
Discovered in ancient times Sublimes
Boils at 4827°C, melts at 3600°C
Notes:
Carbon is found free as the mineral graphite or as diamonds. It is essential to all animal and plant life. Graphite found in large crystals is mined, or obtained by heating coke and pitch in furnaces at very high temperatures. Volatiles are driven off and large graphite crystals then grown in the furnace. These crystals are made up of sheets of carbon atoms and are black in color. Graphite is used as a lubricant and when molded with clay, forms pencil lead. Graphite is also used as electrodes for batteries and electric arc furnaces.
Atomic symbol: N
Atomic weight: 14.00674
Atomic number: 7
Electron configuration: 2-5
Oxidation states: ±1, ±2, ±3, +4, +5
State of matter: gas
Non-metal
Discovered in 1772 by Daniel Rutherford
Boils at -195.8°C, melts at -209.86°C
Notes: Nitrogen is an odorless gas, usually obtained by the fractional distillation of liquid air. The process of including nitrogen to combine chemically with other substances is known as the fixation of nitrogen. A lot of nitrogen is used in the fixation process, which produces the raw materials for fertilizers, explosives, drugs, and dyes. It is used in rooms that store explosives, and in light bulbs to lengthen the life of the filament by preventing its oxidation.
