Model
a useful representation of something
Nucleus
The central core of an atom
Proton
a positively charged particle in the nucleus of an atom
Neutron
a neutral particle in the nucleus of an atom
Electron
a negatively charged particle outside the nucleus of an atom
Element
a substance that is made of only one particular type of atom
Chemical symbol
One or two letters that represent an element’s name
Periodic table
a chart that arranges all the known elements by their properties
Molecule
Two or more atoms joined together
Compound
a molecule that consists of two or more different elements
Chemical formula
a group of chemical symbols and numbers that describe describes the types and numbers of elements present in a molecule
Density
The measure of how compact matter is
Technology
The application of knowledge to accomplish a goal
