Atom - Answers The smallest particle of an element that retains its identity in a chemical reaction
Electrons - Answers A negatively charged subatomic particle
Protons - Answers A positively charged subatomic particle found in the nucleus of an atom
Neutrons - Answers A subatomic particle with no charge and a mass of 1 amu; found in the nucleus of an
atom
Nucleus - Answers the tiny, dense central portion of an atom, composed of protons and neutrons
Atomic Number - Answers the number of protons in the nucleus of an atom of an element
Atomic Mass - Answers the weighted average of the masses of the isotopes of an element
Periodic Table - Answers an arrangement of elements in which the elements are separated into groups
based on a set of repeating properties
Period - Answers a horizontal row of elements in the periodic table
Group - Answers a vertical column of elements in the periodic table; the constituent elements of a group
have similar chemical and physical properties
Metals - Answers one of a class of elements that are good conductors of heat and electric current;
metals tend to be ductile, malleable, and shiny
Nonmetals - Answers an element that tends to be a poor conductor of heat and electric current;
nonmetals generally have properties opposite to those of metals
Metalloid - Answers an element that tends to have properties that are similar to those of metals and
nonmetals
Alkali Metals - Answers any metal in Group 1A of the periodic table
Alkaline Earth Metals - Answers any metal in Group 2A of the periodic table
Halogens - Answers a nonmetal in Group 7A of the periodic table
Noble Gases - Answers an element in Group 8A of the periodic table; the s and p sub levels of the
highest occupied energy level are filled
Representative Elements - Answers an element in an "A" group in the periodic table; as a group these
elements display a wide range of physical and chemical properties. in their atoms, the s and p sublevels
in the highest occupied energy level are partially filled