trace element


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element

 [el´ĕ-ment]
1. any of the primary parts or constituents of a thing.
2. in chemistry, a simple substance that cannot be decomposed by ordinary chemical means; elements are the basic components of which all matter is composed.

Chemical elements are made up of atoms, each of which consists of a nucleus with a cloud of negatively charged electrons revolving around it. The two major components of the nucleus are protons and neutrons. The number of protons in the atoms of a particular element is always the same, and therefore the physical and chemical properties of the element are always the same. It is possible, however, for a chemical element to exist in several different forms, the difference depending on the number of neutrons in the nucleus of its atoms. Different forms of the same element are called isotopes.

There are at least 105 different chemical elements known. (See Appendix 6 for a list of the elements, and the symbol, atomic weight, and atomic number of each.) The atomic number of an element is determined by the number of protons in the nucleus of one of its atoms. The mass number of an isotope is determined by the total number of neutrons and protons in the nucleus.
Stable Chemical Elements. A stable chemical element is one that contains an optimal ratio or range of ratios between the number of protons and neutrons in the nucleus. A stable element does not spontaneously transmute into another element and therefore does not give off radiation. The stable elements are those that have an atomic number below 84, except for a few, such as potassium and rubidium, which are weakly radioactive.
Radioactive Chemical Elements. A radioactive chemical element does not contain an optimal proton-to-neutron ratio in its atomic nuclei and therefore readily gives off nuclear particles until all nuclei have attained the optimal combination of protons and neutrons. The spontaneous releasing of its nuclear particles changes the radioactive atom into a new atom (transmutation).ƒ

As radioactive elements disintegrate and form new chemical elements, a tremendous amount of energy is released. This emission of energy and nuclear particles is called radiation. The radiations may be electrically charged particles having size and mass, such as alpha particles and beta particles, or they may be nonparticulate and contain no electrical charges, such as gamma rays. Most radioactive elements give off either alpha or beta particles and at the same time emit gamma radiation.
formed e's of the blood the blood cells.
trace element a chemical element present or needed in extremely small amounts by plants and animals; such elements include manganese, copper, cobalt, zinc, and iron.

trace element

n.
1. A chemical element present in tiny amounts: trace elements in ground water.
2. A chemical element required in minute quantities by an organism to maintain proper physical functioning.

trace element

Any of a group of metal ions present in minimal amounts in the environment, including arsenic, chromium, cobalt, copper, fluorine, iodine, manganese, nickel, selenium, silicon, tin, vanadium and zinc.

trace element

any element that is necessary for the proper working of biological systems in concentrations less than 10–5M. Absence can cause disease and death. For example, boron deficiency causes ‘heart rot’ in sugar beet, and cobalt deficiency causes ‘coast disease’ in Australian sheep and cattle. See THYROID GLAND for iodine deficiency, and ESSENTIAL ELEMENTS.
References in periodicals archive ?
The aim of this study was to assess status of selenium (Se) and other trace elements in relation to soil properties in the arid soils of Al-Jouf region, Saudi Arabia.
Some trace elements have potential to expand the lattice parameters of the synthetic apatite crystal cell along the a-axis such as ferrous (Fe2+), ferric (Fe3+), strontium (Sr2+) and zinc ions (Zn2+) (molar fraction >10%) whereas it shrinks with silicate (SiO44-), carbonate (CO32-), magnesium (Mg2+), Zn2+ (molar fraction < 10%) and titanium ions (Ti4+).SiO44-, CO32-, Zn2+, Fe2+, Fe3+ and strontium ions (Sr2+) can increase the lattice parameters along the c-axis, decreased by Mg2+, nickelous (Ni2+), chromic (Cr3+), cobaltous (Co2+) and Ti4+.
In this special issue there are papers that explore various concepts related with advantages and disadvantages of the presence of trace elements in living organisms.
A number of studies [9-18] assert that trace elements enter the body primarily through water and food intake, then they are carried by the blood by binding them to specific proteins; however, a certain portion of them (which is different for different elements) is present in the blood in an ionized form.
Gender-wise distribution of urinary trace elements of healthy individuals of KPK (n=200)
The reason of present study is to appraise abundance and distribution of major and trace elements of groundwater and soils of Taluka Khairpur.
Trace Elements in hemodialysis and continuous ambulatory peritoneal dialysis patients.
Exploiting dynamic reaction cell inductively coupled plasma mass spectrometry (DRC-ICP-MS) for sequential determination of trace elements in blood using a dilute-and-shoot procedure.
Serum Zn was estimated on atomic absorption spectrometer which is the reference method for the determination of trace elements.Zinc in the current study had a mean concentration of 24.027.03 mol/L (range11.47- 36.72).
Also, perifollicular vasculature and nerves, viruses, alterations in trace elements [3], and endocrine and thyroid abnormality [4] have been hypothesized.
In our study, we use serum trace element concentrations as markers of trace element status in the organism.
Many pollutants including trace elements are released from natural and anthropogenic sources into aquatic environments [1, 2].