Gallium

While silicon based solar cells are the more popular, recent gallium arsenic (GaAs) based cells have been found potentially have the highest efficiencies out of any single-junction solar cells. These cells have been steadily increasing their efficiency rates. This may be due to high quality materials though. GaAs cells…

1. What is the forbidden gap in semiconductors? One electron volt (eV) 2. At absolute zero temperature, semiconductor behaves as Insulator 3. Define electrical conductivity. Electrical conductivity is the ability to conduct an electric current. 4. What are the two types of charge carriers in semiconductors? Electrons and holes are the two types of charge carriers in semiconductor. 5. Define charge carrier. Charge carrier is a particle, which carries electric charge or electric current from one…

Selenium: The Essential Element Introduction Over the years, selenium is known to be the essential element in all forms of life. Selenium is a metalloid belonging to the block p, group 16, period 4. It is a gray metallic rare element widely distributed within Earth’s crust which has an atomic number of 34 and a symbol “Se”. Selenium was discovered in 1817 by Jöns Jacob Berzelius and Johan Gottlieb Gahn after analysing an impurity contaminating the sulphuric acid being produced by a factory…

Space Programs to Venus My science fiction assignment will be about humans preparing to travel to Venus. In this paper, I wall talk about the Soviet Venera 9 mission. My science fiction paper will consist of ways for probes to survive on Venus long enough to work and restore Venus to what it is believed it was: an Earth-like planet. It will talk about the silicon carbide transistors which can withstand the extreme heat, nuclear batteries that can work on Venus as an alternative to solar and…

Gallium scans, Gastric Emptying, MUGA scans, and Spect Brain scans are just a few of the scans that were formed, thanks to the nuclear medicine of today. In 1896, a man by the name of Henri Becquerel discovered that uranium penetrating rays were similar to X-rays. This leads to other numerous discovers like the finding of elements polonium and radium, to the cyclotron invented by Ernest Lawrence that included the ability to produce radioisotopes of different elements. This leads to 1946, where…

The periodic table had been a key factor in many ways to finding new elements, like scandium, silicon, and neon. It has shown new ways those elements could help us by predicting certain elements reactions. While Dimitri Ivanovich Mendeleev is considered to be the creator of the periodic table, there were many contributions that helped the creation of the useful graph be achieved. Between 1817 and 1829 Johann Dobereiner was grouping elements with similar properties into groups of threes,…

Before talking about the elements, the atom must be discussed first. Atoms are the building blocks of everything—from the structures of a building to a household pet. The idea of the atom was first suggested by Democritus, a Greek philosopher born in 460 BC. Democritus hypothesized “that atoms were indivisible and infinite in size and shape as well as firm and completely solid” and that they “existed in a void moving about combining and recombining” (European Graduate School). Later on, a…

Chemistry ERT - ITEM 3 Item 3.1 and 3.2 – Graphs The trend for the number of electrons in the valence shell for an element is clearly seen in this graph. The lowest point of each peak coincides with the Group I alkali metals. From there on, the electron count climbs until a full shell is reached at eight electrons, i.e. the noble gases who have full outer shells. The full shell signals the end of a Period at Group VIII, and then it begins again in Group I in a new Period. There is…

Dalton Ellis Adv. Chemistry Mr. Lawson 6th 1/05/16 Reading Assignment I choose The Disappearing Spoon, by Sam Kean because I read short reviews on all the books on the reading list, and this one seemed the most interesting. After doing some research on the boom I found that it had great reviews online, and was one of the top ten most recommended books in the chemistry genre. This book caught my attention because it gave a brief history of many of the elements, and I was keen to learn how to…

the first scientist to come up with a periodic trend to predict the properties of elements which were not discovered at that time. Therefore, Mendeleev’s periodic table had empty spaces/gaps, so that these elements, once found can be then included. Gallium and Germanium were two such elements. Also in some cases, Mendeleev didn’t strictly follow the rule of ordering…