Chapter 2 Open Stax Chemistry

subatomic particle

one of three particles that make up atoms (protons, neutrons, electrons)

proton

positively charged subatomic particle located in the nucleus of atoms

electron

negatively charged subatomic particle that surrounds the nucleus of an atom

neutron

subatomic particle with no charge located in the nucleus of atoms

nucleus

positively charged center of an atom that contains protons and neutrons

atomic number (Z)

number of protons in the nucleus of an atom

mass number (A)

number of protons and neutrons in the nucleus of an atom

chemical symbol

one, two or three letter abbreviation used to represent an element

isotope

atoms that contain the same number of protons but different numbers of neutrons

molecular formula

gives the number and kind of atoms in a molecule of an element

structural formula

shows the atoms in a molecule and how they are connected

group

vertical column of the Periodic Table

period

horizontal row of the Periodic Table

ionic compound

compound composed of cations and ions (has no net charge)

molecular compound

compound composed of covlently bonded atoms

anion

negatively charged atom or molecule (contains more electrons that protons)

cation

positively charged atom or molecule (contains more protons than electrons)

ion

atom or molecule with a charge (number of protons is not equal to number of electrons)

binary compound

compound that contains two different elements

polyatomic ion

ion composed of of more that one atom