The melting point of an element or compound means the temperatures at which the solid form of the element or compound is at equilibrium with the liquid form. The density of an element is usually expressed graphically with temperatures and air pressures, because these two properties influence density. Traditionally, density is expressed through the Greek letter ro (written as r).Within the SI system of units density is expressed in kilograms per cubic meter (kg/m 3). The density of an element indicates the number of units of mass of the element that are present in a certain volume of a medium. All of the remaining elements are given a value of somewhere between these two extremes. Francium, the element with the lowest possible electro negativity, was given a value of 0,7. Pauling gave the element with the highest possible electro negativity, fluorine, a value of 4,0. The values of electro negativity are not calculated, based on mathematical formula or a measurement. Nobel prize winner Linus Pauling developed this scale in 1932. Pauling's scale is a widely used method to order chemical elements according to their electro negativity. The average is weighted by the relative natural abundances of the element's isotopes.Įlectro negativity measures the inclination of an atom to pull the electronic cloud in its direction during chemical bonding with another atom.
In reference to a certain chemical element, the atomic mass as shown in the periodic table is the average atomic mass of all the chemical element's stable isotopes. The relative occurrence of the isotopes in nature is an important factor in the determination of the overall atomic mass of an element. The total atomic mass of an element is an equivalent of the mass units of its isotopes. The atomic mass of an isotope indicates the number of neutrons that are present within the core of the atoms. Each isotope of a chemical element can vary in mass. Each proton or neutron weighs about 1 amu, and thus the atomic mass in always very close to the mass (or nucleon) number, which indicates the number of particles within the core of an atom this means the protons and neutrons. Most of the mass of an atom is concentrated in the protons and neutrons contained in the nucleus. The name indicates the mass of an atom, expressed in atomic mass units (amu). Ions either have a number of electrons larger (negatively charged) or smaller (positively charged) than the atomic number. Atoms that carry electric charges are called ions. These electrons mainly determine the chemical behaviour of an atom. When an atom is generally electrically neutral, the atomic number will equal the number of electrons in the atom, which can be found around the core. An element and its place within the periodic table are derived from this concept. The atomic number is an important concept of chemistry and quantum mechanics. The atomic number indicates the number of protons within the core of an atom. Separation and Concentration Purification RequestĬhemical properties of elements and compoundsĪtomic number - Atomic mass - Electronegativity according to Pauling - Density - Melting point - Boiling point - Vanderwaals radius - Ionic radius - Isotopes - Electronic schell - Energy of first ionisation - Energy of second ionisation - Standard potential.Plant Inspection & Process Optimalisation.The file size may be a little too big for dial up internet connection. You need Flash Player to open an iPaper file. Virtually any document format is convertable to iPaper, which is embeddable into any website or blog. ( iPaper is a document format built for the Web. Complete Formulae List (Highly recomended)
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