Anatomy & Physiology - Chapter 2
elements - -substance composed of only one type of atom that cannot be broken
into simpler constituents by chemical means
compounds - -chemical combination of two or more elements
atoms - -smallest particle of a chemical element that retains the properties of that
element; particles that combine to form molecules
subatomic particles - -particles that make up atoms; neutrons, protons, electrons
nucleus - -dense, central core of an atom
protons - -positively charged subatomic particle
neutrons - -neutral subatomic particle
electrons - -small, negatively charged subatomic particle
atomic number - -number of protons in an atom of an element
mass number (atomic mass) - -number of protons plus the number of neutrons in an
atom of an element
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, energy level - -limited region surrounding the nucleus of an atom at a certain
distance containing electrons; shell
octet rule - -atoms with fewer or more than eight electrons in the outer energy level
will attempt to lose, gain, or share electrons with other atoms to achieve stability
inert - -stable element; maximum amount of electrons in outer shell
atomic weight - -average atomic mass of an atom of an element as it is found in
nature; atomic weights are usually found in the periodic table of elements
radioisotope - -unstable isotope that undergoes nuclear breakdown and emits
nuclear particles and radiation
decay - -emition of nuclear particles and radiation
chemical reaction - -interaction between two or more atoms that occurs as a result
of activity between electrons in their outermost energy levels
molecules - -two or more atoms covalently joined together
chemical bonds - -energy relationship joining two or more atoms; involves sharing or
exchange of electrons
ions - -electrically charged atom or group of atoms
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elements - -substance composed of only one type of atom that cannot be broken
into simpler constituents by chemical means
compounds - -chemical combination of two or more elements
atoms - -smallest particle of a chemical element that retains the properties of that
element; particles that combine to form molecules
subatomic particles - -particles that make up atoms; neutrons, protons, electrons
nucleus - -dense, central core of an atom
protons - -positively charged subatomic particle
neutrons - -neutral subatomic particle
electrons - -small, negatively charged subatomic particle
atomic number - -number of protons in an atom of an element
mass number (atomic mass) - -number of protons plus the number of neutrons in an
atom of an element
1
Page
, energy level - -limited region surrounding the nucleus of an atom at a certain
distance containing electrons; shell
octet rule - -atoms with fewer or more than eight electrons in the outer energy level
will attempt to lose, gain, or share electrons with other atoms to achieve stability
inert - -stable element; maximum amount of electrons in outer shell
atomic weight - -average atomic mass of an atom of an element as it is found in
nature; atomic weights are usually found in the periodic table of elements
radioisotope - -unstable isotope that undergoes nuclear breakdown and emits
nuclear particles and radiation
decay - -emition of nuclear particles and radiation
chemical reaction - -interaction between two or more atoms that occurs as a result
of activity between electrons in their outermost energy levels
molecules - -two or more atoms covalently joined together
chemical bonds - -energy relationship joining two or more atoms; involves sharing or
exchange of electrons
ions - -electrically charged atom or group of atoms
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