introduction to elements
define elements
elements are one kind of atom
define compound
elements chemically bonded together to form an atom
protons
mass of 1 and 1 positive charge
neutrons
mass 1 and no charge
electron
mass taken as 0 and 1 negative charge
how are particles arranged in an atom
protons and neurons form thr nucleon, electrons circle the nucleon
atomic number
the amount of protons in an atom form the atomic number
how are electrons arranged in shells
the first shell has the lowest energy level -the further the shell the higher the energy level -the first shell can only hold 2 electrons -the second and third shells can hold 8 electrons
patterns in the periodic table
-period number tells you how many electron shells are occupied -the group number tells you the amount of outer electrons
isotopes
-atoms of the same element with the same number of protons but different number of neutrons
shorthand writing isotopes
the nucleon number goes over the electron number
carbon-12 atoms significance
carbon-12 is the standard for atomic mass units alll masses are relative to the carbon 12
how to calculate relative atomic mass
(atomic mass of the first isotopes* % abundance) + (atomic mass of the second isotope* % abundance)