rotational motion of electrons

1. Assignment on physics-ii
Submitted by
Md Jahid Hasan
Id-152-15-5588
Sec-A
Submitted to
Jebun naher sikta
Dep.of CSE
Lecturer on natural science
Daffodil international university

2. Assignment on Rotational motion of electron-
Defination of centrifugal force:
A force that tends to move objects away from the center in a syst
emundergoing circular motion. Centrifugal force keeps the water i
n a whirlingbucket from spilling or throws a rider in a car against
the door when the cargoes around a sharp curve. Centrifugal forc
e is actually a form of inertia. a force,arising from the body's inertia,
which appears to act on a body moving in a circular path and is directed
away from the centre around which the body is moving.
Where does electron gets centrifugal force:
The centrifugal force of the revolving electron just exactly
balances the attractive force of the
nucleus
a planet or a satellite, is electrically charged and it has been
known since the mid-19th century that an electric charge that
undergoes acceleration (changes velocity and direction) will emit

3. electromagnetic radiation, losing energy in the process. A
revolving electron would transform the atom into a miniature
radio station, the energy output of which would be at the cost of
the potential energy of the electron.
actually electrons revolve around the nucleus and centripetal force holds
them in the specifiedorbits it just not hold them in orbits but also is the
cause of electrons rotation around nucleus because electrons and nucleus
are connected to each other with this force like in a cycle wheel the tire is
connected to the wheel excel with spokes excel rotates then tire also rotate
similarly electrons also rotate around nucleus because nucleus is also
rotating about its own axis causes the electrons to rotate around it .this
gives the answer why electrons not require nor lose energy revolving
around nucleus .when viewed from an inertial reference frame,a bodyin
circular motion only requires a centripetal force.Howeverto apply the
inertial laws of motion from the electrons point of view we must include an
imaginary pseudo-force,whichis the centrifugal force. The centrifugal force
acts on the source of the centripetal force to displace it radially from the
center of the Electron path.Its’s clear that ,electronget centrifugal force
from the center of its rotation path.
Why electron rotate in a orbit:
Earth rotatesaround the sun becauseof sun's gravity. If the sun would not
have been there Earth would move in a straight linebut becauseof the
Sun's gravitationalinfluenceits courseis altered and it moves in a nearly

4. circular path.. Similarly, moonrotatesaround Earth due to Earth's
gravitationalinfluence. Thevelocity of these bodieshelps to balancethe
force and prevents the body from falling into the host body and maintaina
orbit.Electronrotateinorbit becauseofmaintaincircumstance.Electrons
are present outsidethe nucleus and arenegativelycharged. Nucleus
consistsof protonsand neutrons, protonsare the positiveguys. Positive
and negativechargesdevelop a attractiveforceknown as Coulomb Force of
attraction. Thisforcehelps the electron to rotateinits orbit. If electrons
rotate, they must release energy and fall into the nucleus.Herecomes Neil
Bhor's theory to rescue. Electrons move in specialized energyshells named
K,L,M,N etc and electronsjump higher and lower shells according tothe
energy they gainor loose. If they are only given some energy, but not
enough to knock them loose,they will move from one orbital to another .
But if there is no other electron in the lower-energy orbital, they will fall
back down again. When they do, they release energy in the form of a
photon (light).Electrons are rotate in orbit,because of electric attraction or
binding coulomb potential.
Why electron travel in a cycle:
Electrons literally travelin a Cycle. Becausethe electron isnegatively
charged it wantsto maintainthesame averagedensityas the background

5. lattice, which of coursehaving lost electronsis positivelycharged. If there is
a slight excess of electrons at some part of the circuit, thenet negative
chargethererepels further electrons being added. Because thecharge
density and thelatticeareboth very large, even very slight imbalancescost
a largeamount of energy to create, so the actsasan incompressiblefluid.
From thereit's all basicallyplumbing. Imaginea water pump connected to
a loop of pipes Voltageisanalogous to water pressure, and current is
analogousto water flow. Electricalresistanceisanalogousto flow resistance
in pipes, and energy is literally energy. Capacitanceisanalogoustothe way
high pressure water compressesslightlyitself causes pipesand closed tanks
to expand slightly and causes thewater level in open tanks to rise.
Against that background themovement of electrons in a wireis analogous
to the flow of water molecules in a pipe. In fact the Drift velocity is
relatively slow for typicalcurrents.Becauseelectronsarenegatively
charged, and becausepositivecurrent wasdefined without knowledge that
it's normally electronsin motion, the flow of electronsis oppositeto current
as standardlydefined. There area few exceptionstothe idea that it'salways
moving electrons carrying (negative) current, but asfar as I know, all such
exceptionsarewell understood. For examplein Electrolyte , it's not
individualelectronsmoving, but electrons attached toatomsor groups of
atomsto form negativelycharged ions. And, at thesame timepositively
charged ionsdrift in the oppositedirectionand contributetothe overall
current flow. Similarlyin Extrinsic semiconductor , impurityatomsabsorb
electrons from the substrateleading to"holes" which move rather asif they
were positively charged particles.Wealsoknow that electronare attracted

6. nucleus,so electron travelin a cycle.Finally, we cantell that electrontravel a
cycle for maintain circumstance.
Reference:
live science,yahoo,info,physics forums,quora,Wikipedia,physicsbook.