Friday, October 28, 2011

ELEMENTS

The element Silicon is a metalloid and its atomic symbol is Si. Its atomic number is 14 while its atomic mass is 28.0855. It was discovered by Jöns Jacob Berzelius, he was a Swedish chemist. He discovered it in 1824 by heating chips of potassium in a silica container and then carefully washing away the residual by-products. Silicon is produced by heating sand with carbon at temperatures at about 2200 degress celcius. It is the seventth most abundant element in the universe!!


The element Iodine has an atomic number of 53 and atomic mass of 126.90047. It was discovered a French chemist called Barnard Courtois in 1811. Courtois was extracting sodium and potassium compounds from seaweed ash. Once the compounds were removed, he decided to add sulfuric acid to further process the ash. On accident he added too much acid and a purple colored cloud came from the mass. The gas condensed on metal objects in the room, creating solid iodine. Today, iodine is chiefly obtained from deposits of sodium iodate and sodium. The human body requires small amounts of Iodine. It is part of a hormone produced by the thyroid gland that controls the body's rate of physical and mental development.

Silver is a transition metal and its symbol is Ag. Its atomic number is 47 and its atomic mass is 107.8682. Archaeological evidence suggests that people have been using silver for at least 5000 years! So a scientist never really "found" silver. Silver can be obtained from pure deposits, from silver ores such as argentite and horn silver, and with deposits of ores containing led, gold, or copper.




Nitrogen is a nonmetal and its symbol is N. Its atomic number is 7 and its atomic mass is 14.0067. It was discovered by the Scottish physician Daniel Rutherford in 1772. It makes up 78% of the earths atmosphere and it is the 5th most abundant element! It is obtained from liquefied air through a process known as fractional distillation.

Wednesday, October 12, 2011

Neon Signs

Neon is an element on the periodic table. It is used in many signs especially at night because of the birght colors it can give off. Neon signs are made up of many different gases. It even is the 5th most abundant gas on Earth! There a re types of neon gases and  they are Helium, Argon, Krypton, Neon, and Xenon. Helium emits a pinkish-red glow, Krypton emits a yellow-white light, Argon emits sky blue, Xenon emits a bright lavender light, and neon emits a red colored light.