Question | Answer |
Law of Multiple Proportions | When two elements form more than one compound, the masses of one element in these compounds for a fixed mass of the other element are in rations of small whole numbers. |
Isotope | Atoms whose nuclei have the same atomic number but different mass numbers. |
Ionic compound | A compound composed of cations and anions. |
Ion | An electrically charged particle obtained from an atom or a chemically bonded group of atoms by adding or removing electrons. |
Inorganic Compound | Compounds composed of elements other than carbon. |
Hydrocarbon | Compounds containing only carbon and hydrogen. |
Hydrate | A compound that contains water molecules weakly bound in its crystals. |
Group (of the periodic table) | The elements in any one column of the periodic table. |
Functional Group | A reactive portion of a molecule that undergoes predictable reactions. |
Fractional (Isotopic) Abundance | The fraction of the total number of atoms that is composed of a particular isotope. |
Formula Unit | The group of atoms or ions explicitly symbolized in the formula. |
Electron | A very light, negatively charged particle that exists in the region around the atom's positively charged nucleus. |
Chemical Nomenclature | The systematic naming of chemical compounds. |
Chemical Formula | A notation that uses atomic symbols with numerical subscripts to convey the relative proportions of atoms of the different elements in a substance. |
Chemical Equation | The symbolic representation of a chemical reation in terms of chemical formulas. |
Cation | A positively charged ion. |
Binary Compound | A compound composed of only two elements. |
Atomic Theory | An explanation of the structure of matter in terms of different combinations of very small particles. |
Atomic Symbol | A one- or two- lettered notation used to represent an atom corresponding to a particular element. |
Atomic Number (Z) | The number of protons in the nucleus of an atom. |
Atomic Mass Unit (AMU) | A mass unit equal to exactly one-twelfth the mass of a carbon-12 atom. |
Atomic Mass | As a general term, the mass of an individual atom. |
Atom | An extremely small particle of matter that retains its identity during chemical reactions. |
Anion | A negatively charged ion. |
Reactant | A starting substance in a chemical reaction. |
Proton | A particle found in the nucleus of the atom. It has a positive charge equal in magnitude, but opposite in sign, to that of the electron and a mass 1836 times that of the electron. |
Product | A substance that results from a chemical reaction. |
Polymer | A very large molecule made up of a number of smaller molecules repeatedly linked together. |
Polyatomic Ion | An ion consisting of two or more atoms chemically bonded together and carrying a net electric charge. |
Periodic table | A tabular arrangement of elements in rows and columns, highlighting the regular repetition of properties of the elements. |
Period (of the periodic table) | The elements in any one horizontal row of the periodic table. |
Oxoacid | An acid containing hydrogen, oxygen, and another element (often called the central element). |
Organic Compound | Compounds that contain carbon combined with other elements, such as hydrogen, oxygen, and nitrogen. |
Nuclide | A particular atom characterized by a definite atomic number an mass number. |
Nucleus | The atom's central core. |
Nonmetal | An element that does not exhibit the characteristics of a metal. |
Neutron | A particle found in the nucleus of an atom. It has a mass almost identical to that of the proton but no electric charge. |
Monomer | The small molecules that are linked together to form a polymer. |
Monatomic Ion | An ion from a single atom. |
Molecule | A definite group of atoms that are chemically bonded together- that is, tightly connected by attractive forces. |
Molecular Formula | A chemical formula that gives the exact number of different atoms of an element in a molecule. |
Metalloid (semimetal) | An element having both metallic and nonmetallic properties. |
Metal | A substance or mixture that has a characteristic luster or shine, is generally a good conductor of heat and electricity, and is malleable and ductile. |
Mass Number (A) | The total number of protons and neutrons in a nucleus. |