atomic radii		These elements have characteristics of metals and nonmetals.
electron		Superman might avoid this one.
properties		The most reactive metal.
rare earth		Uranium is an example of a ________ ________ element.
calcium		The symbol for this element is Sn.
aluminum		As you move from left to right across the periodic table the _______________ energy of the atom will increase.
atomic number		Has 19 protons
proton		Differences in reactivity among the akaline earth metals are shown by ways they react with water.
gold		Family with a member which is important for resipration and another for producing compounds which are real stinky.
Democritus		Most elements are some type of __________.
periodic		This number tells you how many protons are in one atom of an element.
compact		This family contains the element upon which all life on Earth is based.
carbon		The most reactive nonmetal.
Demitri Mendeleev		Most nonmetals are either a solid or ________ at room temperature.
nitrogen		This element has the same number of valence electrons as magnesium and beryllium.
oxygen		The symbol for this element is Na.
carbon		Means "a repeatable pattern".
potassium		Subatomic particle with a positive charge
mendelevium		Element with an atomic mass of 12.011
neon		Which is the more reactive metal, rubidium or magnesium?
bromine		The electrons in the outer energy level of an atom.
sulfur		The horizontal rows are referred to as ____________ .
tin		Las Vegas uses this innert gas a lot to make brightly lit signs.
arsenic		How many periods does the periodic table have?
iron		As you move from left to right across the periodic table the _______ ______ gets smaller.
rubidium		The most abundant element in the Earth's crust.
metalloids		This metalloid is important to the electronics industry.
nitrogen		Most people put great value in this transition metal.
outer		How many metalloids are listed on the periodic table?
ionization		Subatomic particle with a negative charge.
group		Group 17 or 7A are called the __________.
metal		Does selenium have more in common with sulfur or bromine?
carbon		Atoms that have the same number of protons but different number of neutrons.
oxygen		Group 1 or 1A are called the __________ metals.
lithium		The most abuntant metal in the Earth's crust.
isotopes		The columns are referred to as ____________ .
seven		This nonmetal is the most common element in the Earth's atmosphere.
alkali		Group 2 or 2A are called the _______________ metals.
fluorine		The ancient Greek who first proposed the existance of atoms.
sodium		Used with carbon to make steel.
neutron		Nobel gases have a full __________ energy level.
water		The only nonmetal which is a liquid at room temperature.
valence		Elements in the same group have similar _______________ .
halogens		Copper is an example of a ____________ metal.
noble gases		The only metal that is a liquid at room temperature.
periods		These elements have 7 valence electrons.
halogens		Subatomic partile with a neutral charge
krypton		Except for water most of the compounds in your body contain this element.
gas		Oderless, colorless and nonreactive.
solid		This family contains two elements often found in plant fertilizers.
groups		Used in the rechargeble batteries.
hydrogen		The element with the the smallest atom, yet the most abundant element in the universe.
nickle		Five cents.
transition		The rare earth elements are placed below the periodic table to make the table more _________.
seven		On the periodic table elements are arranged by increasing atomic ____________.
mercury		Atoms in the same ________ have the same number of valence electrons.
number		Almost all metals are ________ at room temperature.
alkaline		First to invent a usable periodic table of the elements.
francium		This metalloid has been used in poisons and insecticides.
silicon		Named after the creator of the periodic table.