Download The arrangement of the subatomic particles within the atom

Atomic Structure
y The arrangement of the subatomic
particles within the atom
determines the chemical properties
of the elements
{How
they interact with one another
{The types of ions and structures that
they form
Subatomic Particles
y Proton
{The
positively charged particle
{Found in the nucleus
{Accounts for the mass of the atom, along
with the neutrons
{Determines the identity of the element
y Electron
{The
negatively charged particle in the
atom
{Located in orbitals around the nucleus
{When lost or gained determines the type
of ion formed from the atom
{When an atom loses an electron a
positive ion (cation) is formed
{When an atom gains an electron a
negative ion (anion) is formed
{Interact between atoms to form
chemical bonds in compounds
y Neutron
{ The neutrally charged particle
{ Located in the nucleus
{ With the proton, accounts for the mass of the atom
y The periodic table
gives you 2 basic pieces
of information
{Atomic
number (upper
whole number)
{Atomic mass (lower
decimal number)
y Atomic number
{ Tells you the number of protons
Ù
Since the overall charge on the atom is neutral, the number of
electrons must equal the number of protons
y Atomic mass
{ This number is the mass of the nuclear particles
Ù
{
{
The nucleus is comprised of protons and neutron so the atomic
mass is the sum of the protons and neutrons
The mass of the electrons is negligible
The atomic mass is not a whole number because it is an
average of the isotopes of the element
Vocabulary
y Ion
{Charged
ÙAtom
particle
that has lost or gained electrons
y Isotope
{Atoms
of the same element with
different numbers of neutrons
y Atomic mass
{Weighted
average mass that takes
into account the mass and
abundance in nature of the isotopes
of the element
ÙMeasured
in atomic mass units (amu)
y Mass number
{Total
number of protons and
neutrons
ÙIsotopes
are indicated by including the
mass number with the symbol I.e. C-14
tells you that the mass of carbon is 14, not
the more common 12.