Periodic Table Unit 3 Flashcards
group 2) are metals with two valence electrons
alkaline earth metals
Columns of elements in the periodic table that share similar properties
groups
elements, usually solid, with a shiny surface; good conductors of electricity and thermal energy (heat)
metals
(group 1 except for Hydrogen) are metals with only one valence electron
alkali metals
(group 17) group of elements that are highly reactive; nonmetals; have 7 valence electrons
Halogens
(group 18) elements that generally do not react with other elements, and which are all gases; have eight valence electrons, except for helium which has two
Noble gases
semimetals, have physical properties of both metals and nonmetal
Metalloids
rows of elements in the periodic table arranged by atomic number , energy levels
periods
elements that are poor conductors of electricity and heat
nonmetals
Characteristics, like size, type, and reactivity of the atoms increase or decrease along a row or column of the periodic table.
periodic trend
(groups 3-12) elements that have valence electrons at two different energy levels; do not follow valence rules
Transition Metals
the electrons in the outermost energy level of an atom that influence how an element will react with other substances
valence electrons
rate at which a chemical substance tends to undergo a chemical reaction
reactivity
Elements in the same group have the same number of _____.
valence
Elements in the same period have the same number of _____.
energy levels