A substance that cannot be converted or broken down into simpler substances, and is the primary ingredient of matter.
The basic unit of matter, the defining structure of an element.
Positively charged particle in the nucleus of an atom.
Negatively charged particle found in all atoms, also acts as carrier of electricity in solids.
Particle with the same mass as a proton, with no electric charge. Present in the nucleus of all atoms except hydrogen.
Number of protons in the nucleus of an atom, determining an element's properties.
Mass of an atom, measured in atomic mass units. Value is nearly the same as the sum of protons and neutrons.
A row on the periodic table of elements.
A column in the periodic table of elements.
The degree to which a material conducts electricity or heat.
The way in which the surface of a mineral reflects light.
Substance formed when two or more elements are chemically bonded together.
Particle created when two or more elements are chemically bonded together.
The form of matter is changed, but no chemical reaction occurs.
A usually irreversible chemical reaction where the atoms in a substance are rearranged, creating a new substance.