Periodic-als Vocabulary
- group: a group is a column of elements in the periodic table of the chemical elements.
- periods: elements that are arranged in a series of rows
- elements: one of a class of substances that cannot be separated into simpler substances by chemical means.
- compound:composed of two or more parts, elements
- atomic number: the number of positive charges or protons in the nucleus of an atom of a given element
- atomic mass: the mass of an isotope of an element measured in units formerly based on the mass of one hydrogen atom taken as a unit or on 1/16(0.0625) the mass of one oxygen atom, but after 1961 based on 1/12(0.0833) the mass of the carbon-12 atom.
- atom: the smallest component of an element having the chemical properties of the element
- ion: an electrically charged atom or group of atoms formed by the loss or gain of one or more electrons
- valence electron: an electron of an atom, located in the outermost shell (valence shell) of the atom, that can be transferred to or shared with another atom.
- metal: any of a class of elementary substances, as gold, silver, or copper, all of which are crystalline when solid and many of which are characterized by opacity, ductility, conductivity, and a unique luster when freshly fractured.
- nonmetal: an element not having the character of a metal, as carbon or nitrogen
- metalloids: an element that has both metallic and nonmetallic properties, as arsenic, silicon, or boron.
- noble gases: any of the chemically inert gaseous elements of group 8A or 0 of the periodic table: helium, neon, argon, krypton, xenon, and radon.
- alkali metals: any of the group of univalent metals including potassium, sodium,lithium, rubidium, cesium, and francium, whose hydroxides are alkalis.
- alkaline earth metals: any of the group of bivalent metals including barium, radium,strontium, calcium, and, usually, magnesium, the hydroxides of which are alkalis but less soluble than those of the alkali metals.
- halogen: any of the electronegative elements, fluorine, chlorine, iodine,bromine, and astatine, that form binary salts by direct union with metals.
- cation: a positively charged ion that is attracted to the cathode in electrolysis.
- anion: a negatively charged ion, as one attracted to the anode in electrolysis.
- electron affinity: the quantitative measure, usually given in electron-volts, of the tendency of an atom or molecule to capture an electron and to form a negative ion.
- electronegativity(explain the trends): containing negative electricity; tending to migrate to the positive pole in electrolysis.As you move down a group, electronegativity decreases.
- Ionization Energy (explain the trend): the amount of energy required to remove an electron from an atom to form a cation; also called ionization potential. The Ionization Energy increase from bottom to top and left to right in the periodic table.
- Atomic Radius (explain the trend): the radius of an atom; the distance from the atomic nucleus to the outer most stable electron orbital in a atom at equilibrium; also, one-half the distance between nuclei of atoms of the same element. Going from left to right, atomic radius decreases,
- Density: the state or quality of being dense; compactness; closely set or crowded condition.
- Melting Point: the temperature at which a solid substance melts or fuses.
- Reactivity: the quality or condition of being reactive.