When studying the periodic table, all elements play a vital role to our everyday lives; however the element Chromium is very unique. Four atomic theories, the date of its discovery, how it was discovered, who discovered it, the purpose behind its name, its natural state, common uses, formulas, and its location on the periodic table will all be discussed within this paper.
An atomic theory is a model developed to explain the properties and behaviors of atoms. As with scientific theory, an atomic theory is based on scientific evidence available to any given time and serves to suggest future lines of research about atoms. John Dalton’s Atomic Theory of Matter follows closely with this idea. Dalton was an English chemist in the 1800’s that proposed the first modern atomic theory. Dalton’s theory can be called modern because it contained statements about atoms that could be tested experimentally. Even though they are not correct the value lies in the research ideas it contains. These are the five major parts:
1.
All matter is composed of very small particles called atoms.
2.
All atoms of a given element are identical.
3.
Atoms cannot be created, destroyed, or subdivided.
4.
In chemical reactions, atoms combine with or separate from other atoms.
5.
In chemical reactions, atoms combine with each other in simple, whole-number ratios to form combined atoms.
Joseph John Thomson was another theorist. He was an English Physicist in 1897 that atoms were not indivisible. This new idea of a model of an atom was widely known as the plum-pudding atom. It got its name in a comparison to the traditional English plum pudding where the “plums” are negatively charged electrons, and the pudding is a mass of positive charges. Unfortunately Thomson’s theory was soon put to the test and put to rest by Ernest Rutherford between 1906 and 1908.
The nuclear atom theory by the English chemist and physicist Ernest Rutherford studied the effects of bombarding thin gold foil with alpha particles. His conclusion was that the positive charge in an atom must all be packed together in one small region of the atom. This region was named the nucleus. Within his theory Rutherford knew the placement of the electrons created problems.
The fourth atomic theory was a solution to Rutherford’s electron placement dilemma as part of the atomic theory introduced in 1913 by a Danish physicist Niels Bohr. This proposed theory stated that places exist in the atom where electrons can travel without losing energy. These places were soon referred to as “permitted orbits”, like the orbits that planets travel in during their journey around the Sun. Bohr’s atomic model soon became referred to as the planetary atom. After numerous scientists tested his theory, it became an accepted model by 1930. The model of the atom consisted of two parts, a nucleus whose positive charge was known to be due to tiny particles called protons, and one or more electrons arranged in distinct orbits outside the nucleus.
Chromium was discovered in 1797, by Louis Nicolas Vauquelin. Chromium is derived from the Greek word “chroma” meaning color. Two French chemists, Antoine Francois de Fourcroy and Rene Just Hauy, suggested the name Chromium because it forms so many different colored compounds. The colors range from purple and black to green, orange and yellow. Vauquelin first found Chromium in the mineral Crocoite, also known as lead chromate. Crocoite was used as a pigment, so it only became natural to also use Chromium as a pigment after its discovery.
The natural state of Chromium comes from Chromite a solid metal. Nearly all naturally occurring Chromium is in the trivalent state, usually in combination with iron or other metal oxides. Chromium has many common uses, but three quarters is used in alloys, the melting or mixing of two or more metals. Stainless steel, chrome plating, anodized aluminum, and a metal polish are a few of its common uses. It is also used in the making of stereo and video tapes. Chromium salts are used in the tanning process of leather and because of its color spectrum it is also used in making synthetic rubies and emeralds. One of the most interesting and hidden uses of Chromium however, is its use as a needed mineral in the human body. Although the amount required by the body is very small it plays a significant role in human nutrition. Without the element present the body cannot regulate the amount of glucose, or sugar, in the blood. Ongoing research with Chromium and its treatment surrounding diabetes is also significant.
Formulas for Chromium are included next:
1.
Chromium difluoride

CrF2
2.
Chromium dichloride

CrCl2
3.
Chromium tetrabromide
CrBr4
4.
Chromium triiodide

CrI3
5.
Chromium trioxide

CrO3
6.
Chromium sulphide

CrS
7.
Chromium selenide

CrSe
8.
Chromium nitride

CrN
9.
Chromium hexacarbonyl
Cr(CO)6
10.
Chromium tritelluride

Cr2Te3

Lastly, the Chromium can be found in the center of the Periodic Table. Because it is a transition metal it is in groups 3 thru 12. This group helps to form a relationship between the right and left sides of the periodic table. Transition metals also help to form distinctive colors in compounds. These elements have similar physical and chemical properties. They also all contain bright shiny surfaces and high melting points.
Chromium is definitely an interesting and unique element. Its wide variety of uses, along with its importance to the human body, give Chromium an edge on some other elements.