Download Modern Atomic Theory Notes

Modern Atomic Theory Notes
Present-Day model of the atom
After many scientists, it has been established that electrons act like both
___________________ and ___________________. Like light waves, electrons can
change direction through ______________________.
____________________ is the bending of a wave as the wave passes by the edge of
an object. _________________________, like waves, can interfere with each other.
The modern model of the atom takes into account both the _____________________
and _____________________ properties of electrons. According to this model,
electrons are located in ___________________, regions around a nucleus that
correspond to specific energy levels.
___________________ are regions where electrons are likely to be found. Orbitals
are sometimes called ____________________________________ because they do
not have sharp boundaries.
The Structure of an Atom Notes
Atoms have 3 subatomic particles:
• ________________________
• ________________________
• ________________________
Particle
Relative Mass
Charge
Location
(amu stands for _____________ ____________________)
Atomic number =
Since atoms are neutral:
The mass number of an atom is:
To find the mass number on the periodic table, round the atomic mass to the nearest
whole number.
To find the # neutrons:
# neutrons =
Atomic #
Mass #
Carbon
6
12
Sulfur
16
32
# protons
# electrons # neutrons
Isotopes
Not all atoms of a particular element have the same # of _____________________,
but they have the same atomic number (same # of ______________________).
These are called _________________________________.
Three main isotopes of carbon:
Isotope
# protons
# neutrons
Mass Number = ________
Atomic Number = ________