Unit 15-Periodic Table Study Guide Graded A+

compound {Ans: a substance formed by two or more elements}period {Ans: rows of the periodic table, also the number of energy levels.}non-metal {Ans: elements that are dull in appearance, poor conductor of heat and electricity; a chemical element lacking typical metallic properties}group/family {Ans: columns of the periodic table also have same number of valence electrons}alkali metals {Ans: Group 1 on PT.. Highly reactive and form stable compounds.}Halogens {Ans: Contains nonmetals, 7 valence electrons in it's outermost energy level. Very reactive Group 17}mixture {Ans: A combination of two or more substances that are not chemically combined}metalloid {Ans: an element that has some characteristics of metals and some characteristics of nonmetals}metal {Ans: a class of elements characterized by physical properties that include shininess, malleability, ductility, and conductivity}reactivity {Ans: the ability of a substance to combine chemically with another substance}atomic mass {Ans: total mass of the protons and neutrons in an atom}noble gasses {Ans: non-metals, group 18, the most non-reactive elements}element {Ans: A pure substance made of only one kind of atom}valence electron {Ans: Electrons on the outermost energy level of an atom}molecule {Ans: two or more atoms