Matter
Anything that takes up space and has mass.
Mass
A measure of how much matter an object has.
Atom
Basic building blocks of matter consisting of a nucleus (Protons & neutrons) and electrons surrounding the nucleus.
Proton
Positively charged subatomic particle; 1 of 2 that make up an atomic nucleus.
Neutron
A neutral (not charged) subatomic particle; 1 of the 2 particles that make up an atomic nucleus.
Electron
Negatively charged subatomic particle found outside of the nucleus.
Nucleus
Center of an atom where the protons & neutrons are located.
Electron Cloud
A diffuse region of charge surrounding an atomic nucleus; the region in which electrons are found.
Valence Electrons
Electrons that occupy the outermost regions, those farthest from the nucleus of an atom.
Element
A substance that is composed of a single type of atom, as defined by the number of protons in the nucleus.
Types of Matter
Subatomic particles: Protons, Neutrons, Electrons.
Compound
A chemical that contains at least 2 different types of atoms in a fixed ratio.
Molecule
Exact number of atoms of one type of element or more than one type of element that are held together by covalent bonds.
Chemical Bonds
Attractive forces that hold atoms together.
Ion
An atom with a net electric charge.
Cation
(+) charged ion.
Anion
(-) charged ion.
Periodic Table of the Elements
A tabular arrangement of the chemical elements organized by their atomic number.
Group
Columns in the periodic table.
Period
Rows in the periodic table.
Family
Elements within a group that have the same number of valence electrons.
Metals
Atoms that tend to lose electrons; good conductors of heat & electricity.
Nonmetals
Atoms that have electrons that are tightly associated with the nucleus; poor conductors.
Metalloids
Atoms that are shiny like metals but have intermediate electrical conductivity.
