Help with Periodic Table of the Elements?

Question

Need to write out and assignment on Cadmium (Cd 48th element) and the discoverer of it. Any freaky smart people that can help me?

Answer 1

Cadmium (IPA: /ˈkadmiəm/) is a chemical element in the periodic table that has the symbol Cd and atomic number 48. A relatively rare, soft, bluish-white, transition metal, cadmium is known to cause cancer and occurs with zinc ores. Cadmium is used largely in batteries.

Production
Cadmium is a common impurity in zinc, and it is most often isolated during the production of zinc. Zinc sulfide ores are roasted in the presence of oxygen converting the zinc sulfide to the oxide. Zinc metal is produced either by smelting the oxide with carbon or by electrolysis in sulfuric acid. Cadmium is isolated from the zinc metal by vacuum distillation if the zinc is smelted, or cadmium sulfate is precipitated out of the electrolysis solution.[1]


[edit] Notable characteristics
Cadmium is a soft, malleable, ductile, bluish-white bivalent metal which can be easily cut with a knife. It is similar in many respects to zinc but reacts to form more complex compounds.

The most common oxidation state of cadmium is +2, though rare examples of +1 can be found.


[edit] Applications
About three-fourths of cadmium is used in batteries (especially Ni-Cd batteries) and most of the remaining one-fourth is used mainly for pigments, coatings and plating, and as stabilizers for plastics. Other uses;

Used in some of the lowest melting alloys.
Due to a low coefficient of friction and very good fatigue resistance, it is used in bearing alloys.
6% of cadmium finds use in electroplating.
Many kinds of solder contain this metal.
As a barrier to control nuclear fission.
Compounds containing cadmium are used in black and white television phosphors and also in the blue and green phosphors for color television picture tubes.
Cadmium forms various salts, with cadmium sulfide being the most common. This sulfide is used as a yellow pigment. Cadmium selenide can be used as red pigment, commonly called cadmium red. To painters who work with the pigment, Cadmium yellows, oranges and reds are the most potent colours to use. In fact,during production these colours are significantly toned down before they are ground with oils and binders, or blended into watercolours, gouaches, casesin, acrylics and other paint and pigment formulations. These pigments are toxic and it is recommended to use a barrier cream on your hands to prevent absorption through the skin when working with them. There is no such thing as cadmium blue, green or violet.
Used in some semiconductors such as cadmium sulfide, cadmium selenide, and cadmium telluride, which can be used for light detection or solar cells. HgCdTe is sensitive to infrared.
Some cadmium compounds are employed in PVC as stabilizers.
Used in the first neutrino detector.
Used to block voltage-dependent calcium channels from fluxing calcium ions in molecular biology.
See also Cadmium compounds.


[edit] History
Cadmium (Latin cadmia, Greek kadmeia meaning "calamine") was discovered in Germany in 1817 by Friedrich Strohmeyer. Strohmeyer found the new element within an impurity in zinc carbonate (calamine) and for 100 years Germany remained the only important producer of the metal. The metal was named after the Latin word for calamine since the metal was found in this zinc compound. Strohmeyer noted that some impure samples of calamine changed color when heated but pure calamine did not.

Even though cadmium and its compounds are highly toxic, the British Pharmaceutical Codex from 1907 states that cadmium iodide was used as a medicine to treat "enlarged joints, scrofulous glands, and chilblains".

In 1927, the International Conference on Weights and Measures redefined the meter in terms of a red cadmium spectral line (1m = 1,553,164.13 wavelengths). This definition has since been changed (see krypton).


[edit] Occurrence

Cadmium metalCadmium-containing ores are rare and when found they occur in small quantities. Greenockite (CdS), the only cadmium mineral of importance, is nearly always associated with sphalerite (ZnS). Consequently, cadmium is produced mainly as a byproduct from mining, smelting, and refining sulfide ores of zinc, and to a lesser degree, lead and copper. Small amounts of cadmium, about 10% of consumption, are produced from secondary sources, mainly from dust generated by recycling iron and steel scrap. Production in the United States began in 1907 but it was not until after World War I that cadmium came into wide use.

See also Category:Cadmium minerals.

[edit] Isotopes

Image of the violet light from a helium cadmium metal vapor laser. The highly monochromatic color arises from the 441.563 nm transition line of cadmium.Naturally occurring cadmium is composed of 8 isotopes. For two of them, natural radioactivity was observed, and other three are predicted to be radioactive but their decays were never observed, due to extremely long half-life times. The two natural radioactive isotopes are 113Cd (beta decay, half-life is 7.7 X 1015 years) and 116Cd (two-neutrino double beta decay, half-life is 2.9 X 1019 years). Other three ones are 106Cd, 108Cd (double electron capture), and 114Cd (double beta decay); only lower limits on their half-life times have been set. At least three isotopes - 110Cd, 111Cd, and 112Cd - are absolutely stable. Among the isotopes absent in the natural cadmium, the most long-lived are 109Cd with a half-life of 462.6 days, and 115Cd with a half-life of 53.46 hours. All of the remaining radioactive isotopes have half-lifes that are less than 2.5 hours and the majority of these have half-lifes that are less than 5 minutes. This element also has 8 known meta states with the most stable being 113mCd (t½ 14.1 years), 115mCd (t½ 44.6 days) and 117mCd (t½ 3.36 hours).

The known isotopes of cadmium range in atomic weight from 96.935 u (97Cd) to 129.934 amu (138Cd). The primary decay mode before the second most abundant stable isotope, 112Cd, is electron capture and the primary modes after are beta emission and electron capture. The primary decay product before 112Cd is element 47 (silver) and the primary product after is element 49 (indium).


[edit] Precautions
Main article: Cadmium poisoning

Cadmium is toxicCadmium has no constructive purpose in the human body. This element and solutions of its compounds are toxic even in low concentrations, and will bioaccumulate in organisms and ecosystems. Chronic poisoning by cadmium is called Itai-itai disease. One possible reason for its toxicity is that it interferes with the action of zinc-containing enzymes. Zinc is an important element in biological systems, but cadmium, although similar to zinc chemically in many ways, apparently does not substitute or "stand in" for it well at all. Cadmium may also interfere with biological processes containing magnesium and calcium in a similar fashion. Pathways of human contact include soil contamination from industrial releases or landfill and associated leachate processes.

Inhaling cadmium laden dust quickly leads to respiratory tract infection and kidney problems which can be fatal (often from renal failure). Ingestion of any significant amount of cadmium causes immediate poisoning and damage to the liver and the kidneys.

Compounds containing cadmium are also carcinogenic [2], and can induce many types of cancer [3].

Cadmium poisoning is the cause of the itai-itai disease, which literally means "ouch ouch" in Japanese. In addition to kidney damage, patients suffered from osteoporosis and osteomalacia.

While working with cadmium it is important to do so under a fume hood to protect against dangerous fumes. Silver solder, for example, which contains cadmium, should be handled with care. Serious toxicity problems have resulted from long-term exposure to cadmium plating baths.

Answer 2

Atomic number
48

Atomic mass
112.4 g.mol -1

Electronegativity according to Pauling
1.7

Density
8.7 g.cm-3 at 20°C

Melting point
321 °C

Boiling point
767 °C

Vanderwaals radius
0.154 nm

Ionic radius
0.097 nm (+2)

Isotopes
15

Electronic shell
[ Kr ] 4d10 5s2

Energy of first ionisation
866 kJ.mol -1

Energy of second ionisation
1622 kJ.mol -1

Standard potential
-0.402 V

Discovered
Fredrich Stromeyer in 1817


Naturally a very large amount of cadmium is released into the environment, about 25,000 tons a year. About half of this cadmium is released into rivers through weathering of rocks and some cadmium is released into air through forest fires and volcanoes. The rest of the cadmium is released through human activities, such as manufacturing.

No cadmium ore is mined for the metal, because more than enough is produced as a byproduct of the smelting of zinc from its ore, sphelerite (ZnS), in which CdS is a significant impurity, making up as much as 3%. Consequently, the main mining areas are those associated with zinc. World production is around 14.000 tonnes per year, the main producing country is Canada, with the USA, Australia, Mexico, JApan and Peru also being the major suppliers.


An exposure to significantly higher cadmium levels occurs when people smoke. Tobacco smoke transports cadmium into the lungs. Blood will transport it through the rest of the body where it can increase effects by potentiating cadmium that is already present from cadmium-rich food.

Other high exposures can occur with people who live near hazardous waste sites or factories that release cadmium into the air and people that work in the metal refinery industry. When people breathe in cadmium it can severely damage the lungs. This may even cause death.

Cadmium is first transported to the liver through the blood. There, it is bond to proteins to form complexes that are transported to the kidneys. Cadmium accumulates in kidneys, where it damages filtering mechanisms. This causes the excretion of essential proteins and sugars from the body and further kidney damage. It takes a very long time before cadmium that has accumulated in kidneys is excreted from a human body.

Other health effects that can be caused by cadmium are:

- Diarrhoea, stomach pains and severe vomiting
- Bone fracture
- Reproductive failure and possibly even infertility
- Damage to the central nervous system
- Damage to the immune system
- Psychological disorders
- Possibly DNA damage or cancer development

Answer 3

Try doing a little research. I think that's what any assignment is supposed to be about.....

cadmium

(kăd´mēm) [from cadmia, Lat. for calamine, with which cadmium is found associated], metallic chemical element; symbol Cd; at. no. 48; at. wt. 112.41; m.p. 321°C; b.p. 765°C; sp. gr. 8.65 at 20°C; valence +2. Cadmium is a lustrous, silver-white, ductile, very malleable metal. It belongs to group IIb of the periodic table, and resembles zinc in its chemical properties. Like zinc, it tarnishes in moist air. Cadmium oxide, a brown powder formed by burning the metal in air, is used in electroplating; it is also made by heating cadmium hydroxide. Cadmium forms a carbonate, a chloride, and several complex ions. Cadmium yellow (the sulfide) is a very durable yellow pigment used in paints. The major use of cadmium is as a coating that is electroplated on iron and steel to prevent corrosion; it is preferable to zinc for protection from alkalies. Cadmium is also used in so-called fusible metals, which are low-melting alloys such as Wood's metal, used in automatic fire sprinklers and alarm systems. Cadmium is used in alkaline nickel-cadmium electric storage cells, which have a greater storage capacity than an equal weight of lead-acid storage cells. It has also found some use in the control of nuclear reactions, since it absorbs neutrons. Cadmium does not occur uncombined in nature; greenochite, a cadmium sulfide mineral found near Greenoch, Scotland, is the only commercial ore. Cadmium is obtained principally as a byproduct of the smelting and refining of ores of zinc, especially zinc sulfides, and of lead and copper. The element was discovered in 1817 by Friedrich Stromeyer.

Answer 4

The website http://www.cadmium.org is very informative. For more sources, see http://www.google.com/search?sourceid=navclient&ie=UTF-8&rls=GGLD,GGLD:2003-51,GGLD:en&q=cadmium

"INTRODUCTION



Cadmium is a naturally occurring minor element, one of the metallic components in the earth’s crust and oceans, and present everywhere in our environment. It was first discovered in Germany in 1817 as a by-product of the zinc refining process. Its name is derived from the Latin cadmia and the Greek kadmeia.

Industrial applications for cadmium were developed in the late 19th and early 20th Century. Cadmium-sulfide based pigments were used as early as 1850 and appeared prominently in the paintings of Vincent Van Gogh in the late 1800s. Thomas A. Edison in the United States and Waldemar Junger in Sweden developed the first nickel-cadmium batteries early in the 20th Century. However, the most significant early use of cadmium was as a corrosion-protection coating on steel.

Releases of cadmium to the environment from the manufacture of cadmium products are well controlled and, today, are insignificant contributors to human exposure to cadmium. Similarly, consumer use and disposal of cadmium-containing products, such as batteries, pigments and coatings, have been shown not to contribute significantly to increased human exposure to cadmium.

Cadmium is recognized to produce toxic effects on humans. Long-term occupational exposure can cause adverse health effects on the lungs and kidneys. Under normal conditions, adverse human health effects have not been encountered from general population exposure to cadmium. Potential risks have been extensively studied and are now tightly controlled. "

Answer 5

Cadmium was discovered by F. Stromeyer in 1817 in Göttingen, Germany, from an impurity in zinc carbonate.

Here is more info:
http://www.chemsoc.org/viselements/Pages/data/cadmium_data.html
http://www.chemsoc.org/viselements/Pages/cadmium.html
http://en.wikipedia.org/wiki/Cadmium