Physical Science, Chapter 4, Elements and the Periodic Table

A term used to describe material that can be pounded into shapes
A class of elements characterized by physical properties that include shininess, malleability, ductility, and conductivity
mass number
The sum of protons and neutrons in the nucleus of an atom
alkaline earth metal
An element in Group 2 of the periodic table.
transition metal
One of the elements in Groups 3 through 12 of the periodic table.
atomic number
The number of protons in the nucleus of an atom.
A negatively charged particle that is found outside the nucleus of an atom.
A positively charged particle that is part of an atom's nucleus.
energy level
The specific amount of energy an electron has.
An atom with the same number of protons and a different number of neutrons from other atoms of the same element.
The central core of the atom.
A horizontal row of elements in the periodic table showing the repeating pattern of their properties
periodic table
A chart of the elements showing the repeating pattern of their properties.
The basic particle from which all elements are made.
Elements in the same vertical column of the periodic table; also called a family.
beta particle
A fast-moving electron that is given off as nuclear radiation.
alkali metal
An element in Group 1 of the periodic table.
The gradual wearing away of a metal element due to a chemical reaction.
The ease and speed with which an element combines, or reacts, with other elements and compounds.
chemical symbol
A one- or two-letter representation of an element.
electrical conductivity
The ability of an object to transfer electric current.
A term used to describe a material that can be pulled out into a long wire.
A radioactive isotope that can be followed through the steps of a chemical reaction or industrial process.
particle accelerator
A machine that moves atomic nuclei at higher and higher speeds until they crash into one another, sometimes forming heavier elements.
A small particle in the nucleus of the atom, with no electrical charge.
atomic mass
The average mass of all the isotopes of an element.
thermal conductivity
The ability of an object to transfer heat.
An element that lacks most of the properties of a metal.
The ability of a substance to spontaneously emit radiation; a property of unstable isotopes.
radioactive decay
The process in which the atomic nuclei of unstable isotopes release fast-moving particles and energy.
gamma radiation
A type of nuclear radiation made of high-energy waves.
alpha particle
A type of nuclear radiation consisting of two protons and two neutrons.
An element found in Group 17 of the periodic table.
inert gas
An element found in Group 18 of the periodic table.
A material that conducts electric current under some conditions.
Elements that have some properties of metals but also have properties that are typical of nonmetals.
diatomic molecule
A molecule consisting of two atoms.