front 1 Elements | back 1 A chemical element is a pure chemical substance consisting of one type of atom distinguished by its atomic number, which is the number of protons in its nucleus. |
front 2 Mixture | back 2 In chemistry, a mixture is a material system made up by two or more different substances which are mixed but are not combined chemically. |
front 3 Compound | back 3 A chemical compound is a pure chemical substance consisting of two or more different chemical elements |
front 4 Molecule | back 4 A molecule is an electrically neutral group of two or more atoms held together by covalent chemical bonds. |
front 5 Alkali metals | back 5 The alkali metals are a group of chemical elements in the periodic table with very similar properties: they are all shiny, soft, silvery, highly reactive metals. |
front 6 Alkali Earth Metals | back 6 The alkaline earth metals are a group in the periodic table. The alkaline earth metals are called the group 2 elements. |
front 7 Halogens | back 7 Any of the elements fluorine, chlorine, bromine, iodine, and astatine, occupying group 7 of the periodic table. They are reactive nonmetallic elements that form strongly acidic compounds with hydrogen, from which simple salts can be made. |
front 8 Noble gases | back 8 Any of the gaseous elements helium, neon, argon, krypton, xenon, and radon, occupying Group 0 (8) of the periodic table. They were long believed to be totally unreactive but compounds of xenon, krypton, and radon are now known. |
front 9 Transition metals | back 9 Any of the set of metallic elements occupying a central block (Groups IVB–VIII, IB, and IIB, or 4–12) in the periodic table, e.g., iron, manganese, chromium, and copper. Chemically they show variable valence and a strong tendency to form coordination compounds, and many of their compounds are colored. |
front 10 Periodic Table | back 10 a table of the chemical elements arranged in order of atomic number, usually in rows, so that elements with similar atomic structure (and hence similar chemical properties) appear in vertical columns. |
front 11 Period | back 11 a set of elements occupying an entire horizontal row in the periodic table. |
front 12 Group | back 12 a combination of atoms having a recognizable identity in a number of compounds. |
front 13 Bonds | back 13 a strong force of attraction holding atoms together in a molecule or crystal, resulting from the sharing or transfer of electrons. |
front 14 electrostatic force | back 14 the forces between particles that are caused by their electric charges. |
front 15 valencies | back 15 the combining power of an element |
front 16 giant ionic lattice | back 16 A giant ionic lattice is a highly regular arrangement of anions and cations |
front 17 ionic bond | back 17 An ionic bond is a type of chemical bond formed through an electrostatic attraction between two oppositely charged ions. |
front 18 ions | back 18 an atom or molecule with a net electric charge due to the loss or gain of one or more electrons. |
front 19 covalent bond | back 19 when elements try and achieve noble gas structures by transferring electrons from one atom to another |
front 20 simple molecular substances | back 20 These contain only a few atoms held together by strong covalent bonds. An example is carbon dioxide (CO2), the molecules of which contain one atom of carbon bonded with two atoms of oxygen. |
front 21 Molten | back 21 a substance liquified by heat |