Student Name: _______________________________
Mrs. Lee – 8th Grade Physical Science
Period #: ______
Date: _____________
Chapter 4 Vocabulary: Elements & the Periodic Table
Electron: A negatively charged particle that is found outside the nucleus of an atom (p 126)
Proton: A positively charged particle that is part of an atom’s nucleus (p 127)
Neutron: A small particle in the nucleus of the atom, with no electrical charge (p 128)
Isotope: An atom with the same number of protons & a different number of neutrons from other
atoms of the same element (p 130)
Atom: The basic particle from which all elements are made (p 125)
Nucleus: The central core of the atom (p 127)
Energy level: The specific amount of energy an electron has (p 127)
Atomic number: The number of protons in the nucleus of an atom (p 129)
Atomic mass: The average mass of all the isotopes of an element (p 132)
Period: A horizontal row of elements showing the repeating pattern of their properties (p 132)
Chemical symbol: A one- or two- letter representation of an element (p 137)
Malleable: A term used to describe material that can be pounded into shapes (p 138)
Mass number: The sum of protons & neutrons in the nucleus of an atom (p 130)
Periodic table: A chart of the elements showing the repeating pattern of their properties (p 132)
Group: Elements in the same vertical column of the periodic table; also called family (p 136)
Metal: A class of elements characterized by physical properties that include shininess,
malleability, ductility, & conductivity (p 138)
Thermal conductivity: The ability of an object to transfer heat (p 139)
Reactivity: The ease & speed with which an element combines, or reacts, with other elements &
compounds (p 139)
Alkali metal: An element in Group 1 of the periodic table (p 140)
Transition metal: One of the elements in Groups 3 through 12 of the periodic table (p 142)
Ductile: A term used to describe a material that can be pulled out into a long wire (p 138)
Ch 4 Vocabulary
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Student Name: _______________________________
Mrs. Lee – 8th Grade Physical Science
Period #: ______
Date: _____________
Chapter 4 Vocabulary: Elements & the Periodic Table
Electrical conductivity: The ability of an object to transfer electric current (p 139)
Corrosion: The gradual wearing away of a metal element due to a chemical reaction (p 139)
Alkaline earth metal: An element in Group 2 of the periodic table (p 141)
Nonmetal: An element that lacks most of the properties of a metal (p 149)
Halogen: An element found in Group 17 of the periodic table (p 153)
Semimetal: Elements that have some properties of metals but also have properties that are
typical of nonmetals (p 155)
Radioactive decay: The process in which the atomic nuclei of unstable isotopes release fastmoving particles & energy (p 159)
Particle accelerator: A machine that moves atomic nuclei at higher & higher speeds until they
crash into one another, sometimes forming heavier elements (p 144)
Diatomic molecule: A molecule consisting of 2 atoms (p 151)
Inert gas: An element found in Group 18 of the periodic table (p 154)
Semiconductor: Elements that can conduct electric current under some conditions but not under
other conditions (p 155)
Alpha particle: A type of nuclear radiation consisting of 2 protons & 2 neutrons (p 160)
Gamma radiation: A type of nuclear radiation made of high-energy waves (p 160)
Radioactivity: The spontaneous emission of radiation by an unstable atomic nucleus ( p 159)
Beta particle: A fast-moving electron that is given off as nuclear radiation (p 160)
Tracer: A radioactive isotope that can be followed through the steps of a chemical reaction or
industrial process (p 162)
Ch 4 Vocabulary
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