CHEMISTRY GLOSSARY
neutron number → neutronski broj
Neutron number (N) is a characteristic property of a specific isotope of an element, equal to the number of neutrons in the nucleus.
Pauling scale → Paulingova skala
Pauling scale is a numerical scale of electronegativities based on bond-energy calculations for different elements joined by covalent bonds. Electronegativity is the power of an atom when in a molecule to attract eletrons to itself. Fluorine is the most electronegative element with a Pauling electronegativity value of 4.
percentage composition of atom in the molecule → postotni sastav atoma u molekuli
Percentage composition of atom in the molecule is a structure of compound presented in the shape of a percentage of its mass, which comes from every element.
electron → elektron
The electron is an elementary particle with a negative electric charge of (1.602 189 2±0.000 004 6)×10-19 C and a mass of 1/1837 that of a proton, equivalent to (9.109 534±0.000 047)×10-31 kg.
In 1897 the British physicist Joseph John (J.J.) Thomson (1856-1940) discovered the electron in a series of experiments designed to study the nature of electric discharge in a high-vacuum cathode-ray tube. Thomson interpreted the deflection of the rays by electrically charged plates and magnets as evidence of bodies much smaller than atoms that he calculated as having a very large value for the charge to mass ratio. Later he estimated the value of the charge itself.
Electrons are arranged in from one to seven shells around the nucleus; the maximum number of electrons in each shell is strictly limited by the laws of physics (2n2). The outer shells are not always filled: sodium has two electrons in the first shell (2×12 = 2), eight in the second (2×22 = 8), and only one in the third (2×32 = 18). A single electron in the outer shell may be attracted into an incomplete shell of another element, leaving the original atom with a net positive charge. Valence electrons are those that can be captured by or shared with another atom.
Electrons can be removed from the atoms by heat, light, electric energy, or bombardment with high-energy particles. Decaying radioactive nuclei spontaneously emit free electrons, called β particles.
electronegativity → elektronegativnost
Electronegativity is a parameter originally introduced by L. Pauling which describes, on a relative basis, the power of an atom to attract electrons. For example, in hydrogen chloride, the chlorine atom is more electronegative than the hydrogen and the molecule is polar, with a negative charge on the chlorine atom.
There are various ways of assigning values for the electronegativity of an element. Pauling electronegativities are based on bond dissociation energies using a scale in which fluorine, the most electronegative element, has the value 4 and francium, the lowest electronegative element, has the value 0.7.
photon → foton
Photon is an elementary particle of zero mass and spin 1/2. The photon is involved in electromagnetic interactions and is the quantum of electromagnetic radiation. The photon may also be regarded as a unit of energy equal to
where h is Planck constant and ν is the frequency of the radiation.
polar solvent → polarno otapalo
Polar solvent is a liquid with polar molecules which dissolves polar compounds, because the charges on the endings of the solvent’s molecules attract the elements from ion crystals.
radioactivity → radioaktivnost
Radioactivity is capability of a spontaneous decay of an atom. In this way a new atom type is formed and radioactive radiation is released. An atom can emit three types of radioactive radiation: positive α-radiation, negative β-radiation and electrically neutral γ-radiation. During radioactive decay one element never emits all types of radiation at the same time.
Citing this page:
Generalic, Eni. "Halogeni elementi." Croatian-English Chemistry Dictionary & Glossary. 29 June 2022. KTF-Split. {Date of access}. <https://glossary.periodni.com>.
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