Question | Answer |
absolute zero | lowest possible temperature; temperature at which particles of matter almost stop moving |
acid | substance that reacts with metals to release hydrogen |
alloy | substance made of a mixture of two or more metals |
atom | smallest part of an element that can be identified as that element |
atomic mass | total mass of the protons and neutrons in an atom |
atomic number | number of protons in the nucleus of an atom |
base | substance formed when metals react with water |
chemical change | change that produces new substances |
chemical equation | statement in which chemical formulas are used to describe a chemical reaction |
chemical formula | way of writing the name of a compound using chemical symbols |
chemical reaction | process in which new substances with new chemical and physical properties are formed |
chemical symbols | shorthand way of writing the names of the elements |
chemistry | study of matter and its reactions |
coefficient | number that shows how many molecules of a substance are involved in a chemical reaction |
compound | substance made up of two or more elements chemically combined |
covalent bond | bond formed when atoms share electrons |
density | mass per unit volume |
electron | atomic particle with a negative electric charge |
elements | simple substances that cannot be broken down into simpler substances |
family (group) | vertical column of elements in the periodic table |
indicator | substance that changes color in acids and bases |
insoluble | not able to dissolve |
ion | an atom with an electrical charge |
ionic bond | bond formed between atoms that have gained and lost electrons |
isotope | atom of an element with the same number of protons but a different number of neutrons |
mass | amount of matter in an object |
matter | anything that has mass and takes up space |
metals | elements that have the properties of luster, ductility, and malleability |
mixture | two or more substances that have been mixed together but not chemically combined |
molecule | smallest part of a substance that has all the properties of that substance |
neutral | neither acidic or basic |
neutron | atomic particle with neither a negative nor a positive electric charge |
nonmetals | elements that have none of the properties of metals |
nucleus | center, or core, of an atom |
organic compound | compound containing carbon |
oxidation | chemical reaction in which electrons are lost |
oxidation number | number of electrons an atom gains, loses, or shares when it forms a chemical bond |
period | horizontal row of elements in the periodic table |
periodic | repeating pattern |
pH scale | measure of the concentration of hydrogen ions or hydroxyl ions in a solution |
physical change | change that does not produce new substances |
product | substance that is formed in a chemical reaction |
proton | atomic particle with a positive electric charge |
reactant | substance that is changed in a chemical reaction |
soluble | able to dissolve |
solute | substance that is dissolved |
solution | mixture in which one substance is evenly mixed with another substance |
solvent | substance in which a solute dissolves |
subscript | number written to the lower right of a chemical symbol |
valence electrons | electrons in an atom's outer energy level |