← Physical Science Part I Export Options Alphabetize Word-Def Delimiter Tab Comma Custom Def-Word Delimiter New Line Semicolon Custom Data Copy and paste the text below. It is read-only. Select All Atom The smallest particle of an element that has the chemical properties of that element. Element A substance that cannot be broken down into any other substance. Compounds Two or more elements chemically combined Chemical Reaction A change in the arrangement of the atoms or molecules of two or more substances that come into contact with each other. This arrangement causes one or more new substances to come into being. Reactant A chemical element or compound that takes part in a chemical reaction. Product The compound as a result of a chemical reaction. Molecule A particle made up of a group of atoms that are chemically bonded. A molecule of water contains two hydrogen atoms and one oxygen atom. Metal One of a large group of chemical elements that heat and electricity can easily move through. About 80% of the know elements are metals. Electrical conductivity Ability to conduct electricity. Thermal conductivity Ability to conduct or transfer heat. Alloy A solution of two or more metals, which has properties of its own. Examples of alloys are steel and bronze. Malleable Capable of being shaped or formed, especially by pressure or hammering. Ductile Easily molded or shaped without breaking into pieces. Periodic Table A table that shows the elements, their atomic number, symbol, and average atomic mass; elements with similar chemical properties are grouped together. Rows are called periods and columns are called groups. Chemical Property Characteristic of matter that describes how it changes when it reacts with other matter. Atomic number The number of protons in the nucleus of an atom. Symbol A written sign that stands for something else.