Beta particle is a charged particle emitted from a radioactive atomic nucleus either natural or manufactured. The energies of beta particles range from 0 MeV to 4 MeV. They carry a single charge; if this is negative, the particle is identical with an electron; if positive, it is a positron.
An unstable atomic nucleus changes into a nucleus of the same mass number but different proton number with the emission of an electron and an antineutrino (or a positron and a neutrino)
Beta-glucans are are naturally occurring polysaccharides that contain only glucose as structural components, and are linked with β-glycosidic bonds. They is the most known powerful immune stimulant. The most active forms of β-glucans are those comprising D-glucose units with β(1→3) links and with short side-chains of D-glucose attached at the β(1→6) position. These are referred to as beta-1,3/1,6 glucan. They are a major component of soluble dietary fiber, which can be found in cereal grains (oats, barley, wheat), yeast, and certain mushrooms (shiitake, maitake).
Binary solution is a mixture of two liquids that are completely miscible one with another. The boiling point of binary solution depends upon the solution composition and there can be three cases:
1. the boiling points of solutions of all compositions lie between the boiling points of clean liquids
2. the boiling points of solutions of any composition lie above the boiling points of clean liquids
3. the boiling points of solutions of some compositions lie below the boiling points of clean liquids
The magnetic field B due to a current-carrying conductor can be determined by Biot-Savart law. The contribution to magnetic field set up at distance r by the current element IdL is given by expression:
where μ0 is permeability constant. It plays a role in magnetic problems equivalent to the role of permittivity constant μ0 in electrostatics problems. In order to obtain B, contributions of all current elements have to be integrated. In case of a long straight conductor, carrying current I, Biot-Savart law gives:
SI unit for magnetic field B is tesla (T).
Permaeability constant μ0 has value 4π×10-7 T m A-1.
Blackbody radiation is the radiation emitted by a perfect blackbody, i.e., a body which absorbs all radiation incident on it and reflects none. The primary law governing blackbody radiation is the Planck Radiation Law, which governs the intensity of radiation emitted by unit surface area into a fixed direction (solid angle) from the blackbody as a function of wavelength for a fixed temperature. The Planck Law can be expressed through the following equation
where λ is the wavelength, h is Planck’s constant, c is the speed of light, k is the Boltzmann constant, and T is the temperature.
Bragg angle (Θ) is the angle between an incident X-ray beam and a set of crystal planes for which the secondary radiation displays maximum intensity as a result of constructive interference. British physicist Sir William Henry Bragg and his son Sir William Lawrence Bragg developed a simple relation for scattering angles, now call Bragg’s law.
which relates the angle θ between a crystal plane and the diffracted X-ray beam, the wavelength λ of the x-rays, the crystal plane spacing d, and the diffraction order n (any integer).
The diffraction experiment as presently considered is intended to provide quantitative information on the lattice constant and shape characteristics of the unit cell.
Born-Haber cycle is a cycle of reactions used for calculating the lattice energies of ionic crystalline solids. For a compound MX, the lattice energy is the enthalpy of the reaction
The standard enthalpy of formation of the ionic solid is the enthalpy of the reaction
The cycle involves equating this enthalpy (which can be measured) to the sum of the enthalpies of a number of steps proceeding from the elements to the ionic solid. The steps are:
1) Atomization of the metal
2) Atomization of the nonmetal
3) Ionisation of the metal
This is obtained from the ionisation potential.
4) Ionisation of the nonmetal
This is electron affinity.
5) Formation of the ionic solids
Equation of the enthalpies gives
from which ΔHL can be found.
Brasses are alloys of copper and zinc (generally 5 % to 40 %). Brass has been known to man since prehistoric times, long before zinc itself was discovered. It was produced by melting copper together with calamine, a zinc ore. Its ductility reaches a maximum with about 30 % zinc and its tensile strength with 45 % although this property varies greatly with the mechanical and heat treatment of the alloy. Typical applications included gears, plumbing ware fittings, adapters, valves and screw machine products. The French horn is a valved brass wind instrument.
Brass may contain small amounts of other alloying elements, such as aluminum, lead, tin, or nickel. Lead can be added as an alloying element resulting in a brass that can be rapidly machined and produces minimal tool wear. Additions of aluminium, iron and manganese to brass improve strength, whilst silicon additions improve wear resistance. Brass containing tin (< 2 % ) is less liable to corrosion in seawater; it is sometimes called naval brass and is used in naval construction.
Bunsen burner is a standard source of heat in the laboratory. German chemist Roberts Bunsen (1811-1899) improved the burner's design, which had been invented by Faraday, to aid his endeavors in spectroscopy. The Bunsen burner has a vertical metal tube through which a fine jet of fuel gas is directed. Air is drawn in through airholes near the base of the tube and the mixture is ignited and burns at the tube’s upper opening. The flow of this air is controlled by an adjustable collar on the side of the metal tube. When the whole is closed a yellow safety flame is displayed. Where as when the whole is open it displays a power dull blue flame with a faint blue outer flame with a vibrant blue core used u for combustion and hearting. The flame can reach temperatures of 1 500 °C.
Burette is a graded glass pipe which on its lower side has a glass faucet by which it can drop a precise quantity of liquid. Inner diameter of a burette must be equal in its whole length, because the accuracy of volume measurement depends upon that. Burettes are primarily used in volumetric analysis for titration with standard solution reagent. Most often Schellbach’s burette is used, graded on 50 mL with division of scale on 0.1 mL. Every burette is calibrated on discharge. For serial determining automatic burettes are used.
Generalic, Eni. "Sửa báo cáo khoản vay nước ngoài." Croatian-English Chemistry Dictionary & Glossary. 29 June 2022. KTF-Split. {Date of access}. <https://glossary.periodni.com>.
Glossary
Periodic Table