Download Electrons Circulating a Nucleus

Electrons Circulating a Nucleus
•Valence electrons are the
electrons contained in the
outermost, or valence,
electron shell of an atom.
Valence electrons are
important in determining how
an element reacts chemically
with other elements:
Neutrons
Inert Gases
HE=Helium
NE=Neon
Ar=Argon
Kr=Krypton
Don’t Interact
K = 2*(12 ) = 2
L = 2*(22 ) = 8
N = 2*(32 ) = 18
N = 2*(42 ) = 32
Protons
Good Conductors
Thus the maximum number of
electrons that each of the
first four shells can hold Is:
IB and IIB
AG=Silver 47
AU= gold atomic #79
CD=Cadmium #48
CU=Copper #29
HG=Mercury
ZN=Zinc #30
RG=roentgen #111
@Copyright David Lubliner NJIT 2007
Animation of Electrons Moving Through A wire (yellow wire)
-1
-1
-1
-1
-1
atom
atom
atom
atom
atom
atom -1
-1 atom
No net gain in electrons (one enters the wire (in yellow) knocks the other
out of its valence shell and takes its place)
atom -1
-1 atom
-1
atom
-1
-1
atom
-1
-1
atom
atom
+
Lets Say each atom has
5 Electrons and 5 Protons with a
net charge
•(+5 and -5)= 0
Atoms with
•(+5 and -4)=+1 (extra proton)
•(+5 and -6)= -1 (extra electron)
• Maximum Speed electromagnetic energy
-1
-1
-1
-1 -1
Atoms
need
electrons
Battery More Protons
More electrons
can travel through empty space is the
speed of light 186,000 miles per second.
•Average speed electrons flow through a
wire 100,000 miles per second.
•Speed electrons flow through human
nerves 100 feet per second.
@Copyright David Lubliner NJIT 2007
Quantum Mechanics (Photons generated)
•The word “quantum” (Latin,
“how much”) in quantum
mechanics refers to a
discrete unit that quantum
theory assigns to certain
physical quantities, such as
the energy of an atom at rest
(see Figure 1, at right). The
discovery that waves have
discrete energy packets
(called quanta) that behave in
a manner similar to particles
led to the branch of physics
that deals with atomic and
subatomic systems
Energy imparted to atom,
electron moves to next
shell
When electron return to
previous shell it gives off
one PHOTON (packet)
of energy
Neutrons
Protons
•In empty space, the
photon moves at c (the
speed of light 186,000
miles/sec) and its energy
E and momentum P are
related by E+cP.
•The photon is the
elementary particle
responsible for
electromagnetic
phenomena. It is the carrier
of electromagnetic radiation
of all wavelengths,
including gamma rays, Xrays, ultraviolet light,
visible light,, infrared light,
microwaves, and radio
waves. The photon differs
from many other
elementary particles, such
as the electron and the
quark, in that it has zero
rest mass
@Copyright David Lubliner NJIT 2007