4.3 DEFINITIONS & NOTES – ATOMIC STRUCTURE
HOW MANY NEUTRONS ARE NECESSARY FOR
STABILITY? (yes write this down)
Try Building some atoms to see if you can determine this.
http://phet.colorado.edu/en/simulation/build-an-atom
STABLE RATIOS
A LITTLE GREATER THAN 1:1
NOT A PERFECT 1:1 RATIO
THIS REPRESENTS A 1:1 RATIO
NEUTRONS : PROTONS
One of the points on the graph is (9,11) what is this element? Sketch it
with its protons, electrons and neutrons.
ENERGY & THE ATOM
ENERGY – the ability to do work. An object has energy if it can exert a force on
something and move it.
KINETIC ENERGY – the energy an object (electron in this case) had due to its
motion (velocity)
POTENTIAL ENERGY – the energy an object has due to its position above a
ground location. An object that can fall can exert a force and move an object and
therefore has energy
GROUND STATE – when an electron is in the lowest position that it can occupy it
is said to be in its ground state.
EXCITED STATE – an object raised above its ground state will be in an excited
state. This means that it has energy and may “fall” to the ground state. It may reach
the excited state by adsorbing energy in various forms THERMAL ENERGY,
ELECTRICAL ENERGY ETC.
THERMAL ENERGY – heat will cause electrons to move to outer
ELECTRICAL ENERGY – if a voltage is applied to a compound the electrons will
jump
When an electron in an excited state falls to a
lower state it gives off energy in the form of
light.
The light given off by each atom is unique and
is therefore a “fingerprint” of the atom.
Scientists can use this light to determine the
atoms inside of a compound. This is how the
make-up of stars is determined.
EM Spectrum Videos:
Emission Spectrum of Hydrogen:
https://www.youtube.com/watch?v=QI50GBUJ48s
Atomic Emission Animation:
https://www.youtube.com/watch?v=8TJ2GlWSPxI
Energy is proportional to Amplitude and Frequency
Shapes of Orbitals -
www.orbitals.com/orb/
http://www.uky.edu/~holler/html/f.html
WHERE THE OUTER MOST ELECTRONS RESIDE
P
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D
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