on a periodic table what does gd for gadolinium stand for?

Answer 1

Notable characteristics
Gadolinium is a silvery white, malleable and ductile rare earth metal with a metallic luster. It crystallizes in hexagonal, close-packed alpha form at room temperature; when heated to 1508 K, it transforms into its beta form, which has a body-centered cubic structure.

Unlike other rare earth elements, gadolinium is relatively stable in dry air; however, it tarnishes quickly in moist air and forms a loosely adhering oxide that spalls off and exposes more surface to oxidation. Gadolinium reacts slowly with water and is soluble in dilute acid.

Gadolinium has the highest thermal neutron capture cross-section of any (known) element, 49,000 barns, but it also has a fast burn-out rate, limiting its usefulness as a nuclear control rod material.

Gadolinium becomes superconductive below a critical temperature of 1.083 K. It is strongly magnetic at room temperature, and exhibits ferromagnetic properties below room temperature.

Gadolinium demonstates a magnetocaloric effect whereby its temperature increases when it enters a magnetic field and decreases when it leaves the magnetic field. The effect is considerably stronger for the gadolinium alloy Gd5(Si2Ge2) [1].


Applications
Gadolinium is used for making gadolinium yttrium garnets, which have microwave applications, and gadolinium compounds are used for making phosphors for colour TV tubes. Gadolinium is also used for manufacturing compact discs and computer memory.

Gadolinium is used in nuclear marine propulsion systems as a burnable poison. The gadolinium slows the initial reaction rate, but as it decays other neutron poisons accumulate, allowing for long-running cores. Gadolinium is also used as a secondary, emergency shut-down measure in some nuclear reactors, particularly of the CANDU type.

Gadolinium also possesses unusual metallurgic properties, with as little as 1% of gadolinium improving the workability and resistance of iron, chromium and related alloys to high temperatures and oxidation.

Because of their paramagnetic properties, solutions of organic gadolinium complexes and gadolinium compounds are used as intravenous radiocontrast agents to enhance images in medical magnetic resonance imaging. Magnevist is the most widespread example.

Besides MRI, gadolinium (Gd) is also used in other imaging. In X-ray, gadolinium is contained in the phosphor layer suspending in a polymer matrix at the detector. Terbium-doped gadolinium oxysulfide (Gd2O2S: Tb) at the phosphor layer is to convert the X-rays releasing from the source into light. Gd can emit at 540nm (green light spectrum = 520 – 570nm), which is very useful for enhancing the imaging quality of the X-ray that are exposed to the photographic film. Beside Gd's spectrum range, the compound also has a K-edge at 50 kiloelectron volt (keV), which means its absorption of X-ray through photoelectric interactions is great. The energy conversion of Gd is up to 20%, which means, one-fifth of the X-ray striking on the phosphor layer can be converted into light photons.

Gadolinium oxyorthosilicate (GSO) is a single crystal that is used as a scintillator in medical imaging equipment like as Positron Emission Tomography (PET). Another new scintillator for detecting neutron is cerium-doped gadolinium orthosilicate (GSO - Gd2SiO5:Ce).

Gadolinium gallium garnet (Gd3Ga5O12) is a material with good optical properties, and is used in fabrication of various optical components and as substrate material for magneto–optical films.

In the future, gadolinium ethyl sulfate, which has extremely low noise characteristics, may be used in masers. Furthermore, gadolinium's high magnetic movement and low Curie temperature (which lies just at room temperature) suggest applications as a magnetic component for sensing hot and cold.

Due to extremely high neutron cross-section of gadolinium, this element is very effective for use with neutron radiography.


History
In 1880, Swiss chemist Jean Charles Galissard de Marignac observed spectroscopic lines due to gadolinium in samples of didymium and gadolinite; French chemist Paul Émile Lecoq de Boisbaudran separated gadolinia, the oxide of Gadolinium, from Mosander's yttria in 1886. The element itself was isolated only recently.

Gadolinium, like the mineral gadolinite, is named after Finnish chemist and geologist Johan Gadolin.

In older literature the natural form of the element is often called an "earth", meaning that element came from the Earth. Accordingly - Gadolinium is the element that comes from the earth, gadolinia. Earths are compounds of the element and one or more other elements. Two common combining elements are oxygen and sulfur. For example, gadolinia contains gadolinium oxide (Gd2O3).


Biological role
Gadolinium has no known biological role. It is used as a component of MRI contrast agents as in the 3+ oxidation state the metal has 7 unpaired f electrons. This causes water around the contrast agent to relax quickly enhancing the quality of the MRI scan.


Occurrence
Gadolinium is never found in nature as the free element, but is contained in many rare minerals such as monazite and bastnäsite. It occurs only in trace amounts in the mineral gadolinite which was also named after Johan Gadolin. Today, it is prepared by ion exchange and solvent extraction techniques, or by the reduction of its anhydrous fluoride with metallic calcium.


Value
In 1994, the cost of gadolinium was about US$ 0.12 per gram, and it has only increased in value by about US$ 0.01 per gram since then.[2]:

1994.....$55 per pound (or $0.115 per gram)
1995.....$55 per pound (or $0.115 per gram)
1996.....$115 per kilogram (or $0.115 per gram)
1997.....$115 per kilogram (or $0.115 per gram)
1998.....$115 per kilogram (or $0.115 per gram)
1999.....$115 per kilogram (or $0.115 per gram)
2000.....$130 per kilogram (or $0.13 per gram)
2001.....$130 per kilogram (or $0.13 per gram)
2002.....$130 per kilogram (or $0.13 per gram)
2003.....$130 per kilogram (or $0.13 per gram)
2004.....$130 per kilogram (or $0.13 per gram)
2005.....$130 per kilogram (or $0.13 per gram)

Compounds
Compounds of gadolinium include:

Fluorides
GdF3
Chlorides
GdCl3
Bromides
GdBr3
Iodides
GdI3
Oxides
Gd2O3
Sulfides
Gd2S3
Nitrides
GdN
Organics
gadodiamide
See also gadolinium compounds.


Isotopes
Main article: Isotopes of gadolinium
Naturally occurring gadolinium is composed of 5 stable isotopes, 154Gd, 155Gd, 156Gd, 157Gd and 158Gd, and 2 radioisotopes, 152Gd and 160Gd, with 158Gd being the most abundant (24.84% natural abundance). 30 radioisotopes have been characterized with the most stable being 160Gd with a half-life of more than 1.3×1021 years (the decay is not observed, only the lower limit on the half-life is known), alpha-decaying 152Gd with a half-life of 1.08×1014 years, and 150Gd with a half-life of 1.79×106 years. All of the remaining radioactive isotopes have half-lifes that are less than 74.7 years, and the majority of these have half lifes that are less than 24.6 seconds. This element also has 4 meta states with the most stable being 143mGd (t½ 110 seconds), 145mGd (t½ 85 seconds) and 141mGd (t½ 24.5 seconds).

The primary decay mode before the most abundant stable isotope, 158Gd, is electron capture and the primary mode after is beta minus decay. The primary decay products before 158Gd are element Eu (Europium) isotopes and the primary products after are element Tb (Terbium) isotopes.


Precautions
As with the other lanthanides, gadolinium compounds are of low to moderate toxicity, although their toxicity has not been investigated in detail. Also, in patients on dialysis, there are data suggesting that it may cause Nephrogenic Systemic Fibrosis, formerly known as Nephrogenic Dermopathy. [3]

this is a little bit long but complete.

hope this helps

Answer 2

Gd Periodic Table

Answer 3

ok well it is Gd = gadolinium atomic # is 64 the atomic mass is 157.25 the ionic charge is 3+ is that what you were looking for

Answer 4

Zinc and lead, eh? How about Link? Or maybe Zead? It doesn't sound very practical for making cuff links out of, but maybe it will serve as the effective zed of the Periodic Table.

Answer 5

I found a site that will let you better understand what you are asking. I used to work in Radiology and I had to learn this so I am thinking its for the same reason.

Answer 6

http://en.wikipedia.org/wiki/Gadolinium go here it has all the info about it... hope that helps!!!

Answer 7

umm u just answered ur own questioin