Ap Chemistry, Chapter Two Vocabulary

1 PART ONE: THE BASIC TOOLS OF CHEMISTRY Chapter Two: Atoms and Elements (Text from Chemistry and Chemical Reactivity, by Kotz, Treichel, and Weaver

Subatomic particles: the three subatomic particles that make up al atoms are protons, electrons, and neutrons Electrons: negatively charged particles that orbit an atom and make up a cathode ray Nucleus: the tiny core of the atom that contains protons and neutrons Atomic number (Z): the number of protons in the nucleus Atomic mass units (u): one-twelfth of the mass of an atom of carbon with six protons and six neutrons Mass number (A): the sum of the protons and neutrons for an atom Atomic weight: the average weight of a representative sample of atoms Mole: the amount of a substance that contains as many elementary entities (atoms, molecules, or other particles) as there are atoms in exactly 12 g of the carbon-12 isotope Avogadro's number: the number of particles needed to make up one mole of any substance; named after Amedeo Avogadro. Equal to 6.0221415 x 1023 Molar mass: the mass in grams of one mole of any element Groups/Families: vertical columns on a periodic table Periods: horizontal rows on a periodic table Metals: elements, most of which are solid, can conduct electricity, are usually ductile and malleable, and can form alloys. Nonmetals: elements that for the most part do not conduct electricity Metalloid: an element that has some of the physical characteristics of a metal but some of the chemical characteristics of a nonmetal Periodicity: periodic repetition of the properties of elements Law of chemical periodicity: the idea that the properties of the elements are periodic functions of atomic number