Accuracy - Answers how close a measurement is to the true value
Precision - Answers The degree to which repeated measurements show the same result.
Compound - Answers A substance made up of atoms of two or more different elements joined by
chemical bonds
Molecule - Answers A group of atoms bonded together
Element - Answers A pure substance made of only one kind of atom
physical change - Answers a change of matter from one form to another without a change in chemical
properties
pure substance - Answers A sample of matter, either a single element or a single compound, that has
definite chemical and physical properties
Anion - Answers A negatively charged ion
Cation - Answers A positively charged ion
atomic mass - Answers The average mass of all the isotopes of an element
Fundamental unit of charge - Answers (also called the elementary charge) equals the magnitude of the
charge of an electron (e) with e = 1.602 × 10−19 C
Isotopes - Answers Atoms of the same element that have different numbers of neutrons
empirical formula - Answers a chemical formula showing the ratio of elements in a compound rather
than the total number of atoms
molecular formula - Answers A chemical formula that shows the number and kinds of atoms in a
molecule, but not the arrangement of the atoms.
Actinide - Answers inner transition metal in the bottom of the bottom two rows of the periodic table
alkali metals - Answers any metal in Group 1A of the periodic table
alkaline earth metals - Answers metallic elements in group 2 of the periodic table which are harder than
the alkali metals and are also less reactive
chalcogen - Answers element in group 16
Halogens - Answers Contains nonmetals, 7 valence electrons in it's outermost energy level. Very reactive
noble gases - Answers Group 18