Element
A substance that cannot be broken down into simpler substances
Atom
Basic unit of matter
Electron
negatively charged particle
Neutron
no charge
Proton
positively charged particle
Molecules
two or more atoms joined together
Periodic Table of Elements
a chart where all the elements are organized into periods and groups according to their properties
Nucleus
Center of an atom
Metalloid
an element that has properties of both metals and nonmetals
metal
an element that is shiny and that conducts heat and electricity well
Dmitri Mendeleev
Created the periodic table
atomic number
the number of protons in an atom
atomic mass
Number of protons and neutrons
atomic symbol
An abbreviation for an element or atom