Vocabulary

Acid-Base reaction:  a reaction that involves the neutralization of an acid and a base.

Anion:  a negative ion

Atom:  the smallest unit of an element

Atomic mass:  the weighted average mass of the atoms in a naturally occurring element

Atomic theory: 

Avogadro's number:  the number of particles in one mole of a substance (6.022 x 1023)

Balanced equation:  a chemical equation where there are equal numbers of atoms each element and charges on both reactant and product sides.

British:  the system of measurement generally used in the USA (includes feet, pounds and seconds)

Cation: a positive ion

CGS:  a metric system of measurement that used centimeters, grams, and seconds as standards

Chemical equation:  a representation of a chemical reaction showing the relative numbers of reactant and product molecules

Chemical property: a characteristic of a substance that when demonstrated changes the identity of the substance

Chemical symbol:  an abbreviation for the name of an element

Chromatography:  the general name for a series of methods for separating mixtures by employing a system with a mobile phase and a stationary phase

Compound:  a substance with constant composition that can be broken down into elements by chemical processes

Concentration:  an expression that relates how solute molecules relate solvent molecules in a solution

Conversion factor:  a ratio of equivalent quantities that is used to change one unit into another

Dimensional analysis:  a method used to convert units by multiplying by ratios equivalent to one

Distillation:  a method for separating the components of a liquid mixture that depends on differences in the ease of vaporization of the components

Electron:  a negatively charged particle that moves around the nucleus of an atom

Element:  a substance that cannot be decomposed into simpler substances by chemical or physical means

Empirical formula:  the simplest whole number ratio of atoms in a compound

Experimental:  numerical values that are based on measurements taken during a laboratory exercise

Exponential notation:  expresses a number as N x 10M, a convenient method for representing a very large or very small number and for easily indicating the number of significant figures

Filtration:  a method for separating the components of a mixture containing a solid and a liquid

Gas forming reaction:  a chemical reaction in which a gas is formed during the reaction

Heterogeneous:  a mixture that has more than one phase

Homogeneous: a mixture that has only one phase

Ionic compound:  a compound that results when a metal reacts with a nonmetal to form a cation and an anion.

Ionic reaction:  a reaction where the component ions of reactant compounds realign to form new compounds

Isotope:  atoms of the same element (the same number of protons) with different numbers of neutrons.  They have identical atomic numbers but different mass numbers.

Law of Conservation of Mass:  mass is neither created or destroyed

Law of Definite Composition:  a compound always contains exactly the same proportion of elements by mass

Law of Multiple Proportions:  a law stating that when two elements form a series of compounds, the ratios of the masses of the second element that combine with one gram of the first element can always be reduced to small whole numbers

Main-group elements:  elements which belong to the Groups 1A – VIIIA

Mass:  the amount of matter a material contains

Mass percentage:  the percent by mass of a component of a mixture or of a given element in a compound

Mixture:  a mixture of variable composition that contains two or more substances

MKS:  a metric system of measurements that uses meters, kilograms, and seconds as basic units

Modela set of assumptions put forth to explain the observed behavior of matter.  The models of chemistry usually involve assumptions about the behavior of individual atoms or molecules

Molality:  the numbers of moles of solute per kilogram of solvent in a solution

Molarity:  mole of solute per volume of solution in liters

Mole:  the number equal to the number of carbon atoms in exactly 12 grams of pure 12C:  Avogadro’s number

Molecular formula:  the exact formula of a molecule, giving the types of atoms and number of each type

Molecular mass:  the mass in grams of one mole of molecules or formula units of a substance; the same as molar mass

Molecule:  a bonded collection of two or more atoms on the same or different elements

Monatomic ion:  a charge particle that contains only one atom

Neutron:  a particle in the atomic nucleus with mass virtually equal to the proton’s but with no charge

Normality:  the number of equivalents of a substance dissolved in a liter of solution

Oxidation-reduction reaction:  a reaction in which one or more electrons are transferred

Physical property:  a characteristic of a substance that when tested does not alter the identity of the chemical

Precipitation reaction:  a reaction in which an insoluble substance forms and separates from the solution

Proton:  a positively charge particle in an atomic nucleus

Recrystalization:  a method for separating components of mixture by producing solid crystals from a solution

Significant figures:  the certain digits of a measurement

Solution:  a homogeneous mixture

Spectral lines:  the emission spectrum of an element

States of matter:  the three different forms in which matter can exist; solid, liquid, and gas

Stoichiometric ratio of moles:  the ratio of the coefficients of two components in a balanced equation

Stoichiometry:  the study of quantities of reactants and products that can be determined from a balanced chemical equation

Subatomic particle:  a particle that is smaller than a hydrogen atom.  Includes protons, electrons, and neutrons

Substance:  a material that has its own unique set of chemical and physical properties.

Theoretical:  computations that are based on values that were not taken from actual measurements

Volume:  the amount of space an object occupies