Phosphorus - WikiVisually
Phosphorus is a radioactive isotope of phosphorus. short half-life of days and decays into sulfur by beta decay as shown in this nuclear equation: . The concept of half-life is illustrated in Figure below for the beta decay of phosphorus to sulfur The half-life of this radioisotope is 14 days. Sulfur (16S) has 24 known isotopes with mass numbers ranging from 26 to 49, four of which are stable: 32S (%), 33S (%), 34S (%), and 36S ( %). The preponderance of sulfur is explained by its production from carbon . "The NUBASE evaluation of nuclear and decay properties" (PDF). Nuclear.
The medical encounter is then documented in the record, which is a legal document in many jurisdictions. Follow-ups may be shorter but follow the general procedure. The diagnosis and treatment may take only a few minutes or a few weeks depending upon the complexity of the issue, the components of the medical interview and encounter are, Chief complaint, the reason for the current medical visit. They are in the patients own words and are recorded along with the duration of each one, also called chief concern or presenting complaint.
History of present illness, the order of events of symptoms. Distinguishable from history of illness, often called past medical history 4.
Quantum mechanical properties of the include a intrinsic angular momentum of a half-integer value, expressed in units of the reduced Planck constant.
As it is a fermion, no two electrons can occupy the same state, in accordance with the Pauli exclusion principle. Like all elementary particles, electrons exhibit properties of particles and waves, they can collide with other particles and can be diffracted like light. Since an electron has charge, it has an electric field. Electromagnetic fields produced from other sources will affect the motion of an electron according to the Lorentz force law, electrons radiate or absorb energy in the form of photons when they are accelerated.
Laboratory instruments are capable of trapping individual electrons as well as electron plasma by the use of electromagnetic fields, special telescopes can detect electron plasma in outer space. Electrons are involved in applications such as electronics, welding, cathode ray tubes, electron microscopes, radiation therapy, lasers, gaseous ionization detectors.
Interactions involving electrons with other particles are of interest in fields such as chemistry.
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The Coulomb force interaction between the positive protons within atomic nuclei and the negative electrons without, allows the composition of the two known as atoms, ionization or differences in the proportions of negative electrons versus positive nuclei changes the binding energy of an atomic system.
The exchange or sharing of the electrons between two or more atoms is the cause of chemical bonding. InBritish natural philosopher Richard Laming first hypothesized the concept of a quantity of electric charge to explain the chemical properties of atoms. Irish physicist George Johnstone Stoney named this charge electron inelectrons can also participate in nuclear reactions, such as nucleosynthesis in stars, where they are known as beta particles. Electrons can be created through beta decay of isotopes and in high-energy collisions.
The antiparticle of the electron is called the positron, it is identical to the electron except that it carries electrical, when an electron collides with a positron, both particles can be totally annihilated, producing gamma ray photons. The ancient Greeks noticed that amber attracted small objects when rubbed with fur, along with lightning, this phenomenon is one of humanitys earliest recorded experiences with electricity.
Poly methyl methacrylate — The same material can be utilised as a casting resin, in inks and coatings, and has many other uses.
Chemically, it is the polymer of methyl methacrylate. PMMA is an alternative to polycarbonate when extreme strength is not necessary. Additionally, PMMA does not contain the potentially harmful bisphenol-A subunits found in polycarbonate and it is often preferred because of its moderate properties, easy handling and processing, and low cost.
The first acrylic acid was created inmethacrylic acid, derived from acrylic acid, was formulated in The reaction between acid and methanol results in the ester methyl methacrylate.
In the German chemist Wilhelm Rudolph Fittig discovered the process that turns methyl methacrylate into polymethyl methacrylate. Inthe brand name Plexiglas was patented and registered by another German chemist, in Imperial Chemical Industries began the first commercially viable production of acrylic safety glass.
During World War II both Allied and Axis forces used acrylic glass for submarine periscopes and aircraft windshields, canopies, common orthographic stylings include polymethyl methacrylate and polymethylmethacrylate. The full chemical name is poly, although often called simply acrylic, acrylic can also refer to other polymers or copolymers containing polyacrylonitrile. The forming temperature starts at the transition temperature and goes up from there. All common molding processes may be used, including molding, compression molding.
The highest quality PMMA sheets are produced by casting, but in this case 6.
- Isotopes of sulfur
Gamma ray — Gamma ray, denoted by the lower-case Greek letter gamma, is penetrating electromagnetic radiation of a kind arising from the radioactive decay of atomic nuclei. It consists of photons in the highest observed range of photon energy, paul Villard, a French chemist and physicist, discovered gamma radiation in while studying radiation emitted by radium. InErnest Rutherford named this radiation gamma rays, Rutherford had previously discovered two other types of radioactive decay, which he named alpha and beta rays.
Gamma rays are able to ionize atoms, and are thus biologically hazardous.
The decay of a nucleus from a high energy state to a lower energy state. Natural sources of gamma rays on Earth are observed in the decay of radionuclides. There are rare terrestrial natural sources, such as lightning strikes and terrestrial gamma-ray flashes, However, a large fraction of such astronomical gamma rays are screened by Earths atmosphere and can only be detected by spacecraft. Gamma rays typically have frequencies above 10 exahertz, and therefore have energies above keV and wavelengths less than 10 picometers, However, this is not a strict definition, but rather only a rule-of-thumb description for natural processes.
Electromagnetic radiation from radioactive decay of nuclei is referred to as gamma rays no matter its energy. This radiation commonly has energy of a few hundred keV, in astronomy, gamma rays are defined by their energy, and no production process needs to be specified. The energies of gamma rays from astronomical sources range to over 10 TeV, a notable example is the extremely powerful bursts of high-energy radiation referred to as long duration gamma-ray bursts, of energies higher than can be produced by radioactive decay.
These bursts of gamma rays are thought to be due to the collapse of stars called hypernovae, the first gamma ray source to be discovered historically was the radioactive decay process called gamma decay.
In this type of decay, a nucleus emits a gamma ray almost immediately upon formation. Paul Villard, a French chemist and physicist, discovered gamma radiation inHowever, Villard did not consider naming them as a different fundamental type. Rutherford also noted that gamma rays were not deflected by a field, another property making them unlike alpha. Gamma rays were first thought to be particles with mass, like alpha, Rutherford initially believed that they might be extremely fast beta particles, but their failure to be deflected by a magnetic field indicated that they had no charge.
Ingamma rays were observed to be reflected from crystal surfaces, Rutherford and his coworker Edward Andrade measured the wavelengths of gamma rays from radium, and found that they were similar to X-rays, but with shorter wavelengths and higher frequency.
This was eventually recognized as giving them more energy per photon 7. Botany — Botany, also called plant science, plant biology or phytology, is the science of plant life and a branch of biology.
Nowadays, botanists study approximatelyspecies of plants of which somespecies are vascular plants. Medieval physic gardens, often attached to monasteries, contained plants of medical importance and they were forerunners of the first botanical gardens attached to universities, founded from the s onwards.
Isotopes of sulfur - Wikipedia
One of the earliest was the Padua botanical garden and these gardens facilitated the academic study of plants. Efforts to catalogue and describe their collections were the beginnings of plant taxonomy, in the last two decades of the 20th century, botanists exploited the techniques of molecular genetic analysis, including genomics and proteomics and DNA sequences to classify plants more accurately. Modern botany is a broad, multidisciplinary subject with inputs from most other areas of science, dominant themes in 21st century plant science are molecular genetics and epigenetics, which are the mechanisms and control of gene expression during differentiation of plant cells and tissues.
Botany originated as herbalism, the study and use of plants for their medicinal properties, many records of the Holocene period date early botanical knowledge as far back as 10, years ago. This early unrecorded knowledge of plants was discovered in ancient sites of human occupation within Tennessee, the early recorded history of botany includes many ancient writings and plant classifications. Examples of early works have been found in ancient texts from India dating back to before BC, in archaic Avestan writings.
His major works, Enquiry into Plants and On the Causes of Plants, constitute the most important contributions to science until the Middle Ages.Nuclear Half Life: Intro and Explanation
In the early 13th century, Abu al-Abbas al-Nabati, and Ibn al-Baitar wrote on botany in a systematic and scientific manner and these gardens continued the practical value of earlier physic gardens, often associated with monasteries, in which plants were cultivated for medical use.
They supported the growth of botany as an academic subject, lectures were given about the plants grown in the gardens and their medical uses demonstrated. Botanical gardens came much later to northern Europe, the first in England was the University of Oxford Botanic Garden inthroughout this period, botany remained firmly subordinate to medicine.
German physician Leonhart Fuchs was one of the three German fathers of botany, along with theologian Otto Brunfels and physician Hieronymus Bock, Fuchs and Brunfels broke away from the tradition of copying earlier works to make original observations of their own.
Bock created his own system of plant classification, physician Valerius Cordus authored a botanically and pharmacologically important herbal Historia Plantarum in and a pharmacopoeia of lasting importance, the Dispensatorium in Naturalist Conrad von Gesner and herbalist John Gerard published herbals covering the medicinal uses of plants, naturalist Ulisse Aldrovandi was considered the father of natural history, which included the study of plants 8.
Fertilizer — A fertilizer or fertiliser is any material of natural or synthetic origin that is applied to soils or to plant tissues to supply one or more plant nutrients essential to the growth of plants.
Fertilizers enhance the growth of plants and this goal is met in two ways, the traditional one being additives that provide nutrients. The second mode by which some fertilizers act is to enhance the effectiveness of the soil by modifying its water retention and aeration and this article, like many on fertilizers, emphasises the nutritional aspect.
The nutrients required for plant life are classified according to the elements. Instead compounds containing these elements are the basis of fertilizers, the macronutrients are consumed in larger quantities and are present in plant tissue in quantities from 0.
Plants are made up of four elements, hydrogen, oxygen, carbon. Carbon, hydrogen and oxygen are widely available as water and carbon dioxide, although nitrogen makes up most of the atmosphere, it is in a form that is unavailable to plants. Nitrogen is the most important fertilizer since nitrogen is present in proteins, DNA, to be nutritious to plants, nitrogen must be made available in a fixed form.
Only some bacteria and their host plants can fix atmospheric nitrogen by converting it to ammonia, phosphate is required for the production of DNA and ATP, the main energy carrier in cells, as well as certain lipids.
Micronutrients are consumed in quantities and are present in plant tissue on the order of parts-per-million, ranging from 0. These elements are present at the active sites of enzymes that carry out the plants metabolism. Because these elements enable catalysts their impact far exceeds their weight percentage, Fertilizers are classified in several ways.
Half-life plot (video) | Nuclei | Khan Academy
They are classified according to whether they provide a single nutrient, multinutrient fertilizers provide two or more nutrients, for example N and P. Fertilizers are also sometimes classified as inorganic versus organic.
Inorganic fertilizers exclude carbon-containing materials except ureas, organic fertilizers are usually plant- or animal-derived matter.
Inorganic are sometimes called synthetic fertilizers since various chemical treatments are required for their manufacture, the main nitrogen-based straight fertilizer is ammonia or its solutions.
Ammonium nitrate is widely used. Urea is another source of nitrogen, having the advantage that it is solid and non-explosive, unlike ammonia and ammonium nitrate. A few percent of the fertilizer market has been met by calcium ammonium nitrate 9.
Root — In vascular plants, the root is the organ of a plant that typically lies below the surface of the soil. Roots can also be aerial or aerating, that is growing up above the ground or especially above water, furthermore, a stem normally occurring below ground is not exceptional either.
Therefore, the root is best defined as the non-leaf, non-nodes bearing parts of the plants body, however, important internal structural differences between stems and roots exist. The sequence of chemical changes which happen to the substrate can then be traced by detecting which molecules contain the phosphorus at multiple time points following the initial treatment.
DNA contains a large quantity of phosphorus in the phosphodiester linkages between bases in the oligonucleotide chain. DNA can therefore be tracked by replacing the phosphorus with phosphorus This technique is extensively used in Southern blot analysis of DNA samples. In this case a phosphoruscontaining DNA probe hybridises to its complementary sequence where it appears in a gel.
Its location can then be detected by photographic film. Plant sciences[ edit ] Phosphorus is used in plant sciences for tracking a plant's uptake of fertiliser from the roots to the leaves. The phosphoruslabelled fertiliser is given to the plant hydroponically or via water in the soil and the usage of the phosphorus can be mapped from the emitted beta radiation. The information gathered by mapping the fertiliser uptake show how the plant takes up and uses the phosphorus from fertiliser.
Typical safety precautions when working with phosphorus include wearing a personal dosimeter to monitor exposure and an acrylic or perspex radiation shield to protect the body.
Dense shielding, such as lead, is less effective due to the high-energy bremsstrahlung produced by the interaction of the beta particle and the shielding.