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21 Cards in this Set

  • Front
  • Back
The smallest particle of an element that retains the chemical nature of the element. A neutral, spherical entity composed of a positively charged central nucleus surrounded by one or more negatively charged electrons.
The average of the masses of the naturally occurring isotopes of an element weighted according to their abundances.
Atomic Mass
A mass exactly equal to 1/12 the mass of a carbon-12 atom.
Atomic Mass Unit(AMU)
The unique number of protons in the nucleus of each atom of an element.
Atomic Number
A one or two letter abbreviation for the English, Latin, or Greek name of an element.
Atomic Symbol
A substance composed of two or more elements that are chemically combined in fixed positions.
A subatomic particle that possesses a unit negative charge and occupies the space around the atomic nucleus.
The simplest type of substance with unique physical and chemical properties. Consists of the only one kind of atom, so it cannot be broken down into any simpler substances.
Atoms of a given atomic number that have different numbers of neutrons and therefore different mass numbers.
A mass law stating that, no matter what its source, a particular chemical compund is composed of the same elements in the same parts by mass.
Law of Definite Composition
A mass law stating that the total mass of substances does not change during a chemical reaction.
Law of Mass Conservation
A mass law stating that if elements A and B react to form two compunds, the different masses of B that combine with a fixed mass of A can be expressed as a ratio of small whole numbers.
Law of Multiple Proportions
The portion of a compound's mass contributed by an element; the mass of an element in a compound divided by the mass of the compound.
Mass Fraction
The total number of protons and neutrons in an atom.
Mass Number
The fraction by mass expressed as a percentage. A concentration term expressed as the mass in grams of solute dissolved per 100g of solution.
Mass Percent
A group of two or more elements and/or compounds that are physically intermingled.
A structure consisting of two or more atoms that are chemically bound together and behave as an independent unit.
An uncharged subatomic particle found in the nucleus, with a mass slightly greater than that of a proton.
The tiny central region of the atom that contains all the positive charge and essentially all the mass.
A subatomic particle found in the nucleus that has a unit positive charge.
A type of matter, either an element or a compound, that has a fixed composition.
Pure Substance