click below
click below
Normal Size Small Size show me how
Chpt 5 vocab
Term | Definition |
---|---|
periodic table | an arrangement of elements in columns, based on a set of properties that repeat from row to row |
period | each row in the table of elements in the periodic table |
group | each column on the periodic table |
periodic law | the pattern of repeating properties |
atomic mass unit | one twelfth the mass of a carbon-12 atom |
metals | elements that are good conductors of electric current and heat |
transition metals | elements that form a bridge between the |
Non metals | elements that are poor conductors of heat and electric current. |
Metalloids | elements with properties that fall between those of metals and nonmetals. |
Valence electron | an electron that is in the highest occupied energy level of an atom. |
Alkali metals | the elements in group 1A. Have a single valence electron |
Alkaline earth metals | Elements in group 2A. Have two valence electrons |
Halogens | elements in group 7A. Have seven valence electrons |
Noble gases | elements in group 8A. Helium has two valence electrons. Each of the others has eight. |