THE
ELECTRIC CHARGE
OF A PARTICLE
(LIKE A PARTICLE’S MASS)
IT IS A PROPERTY OF MATTER
SOME PARTICLES HAVE AN ELECTRIC CHARGE,
OTHERS DO NOT:
THE ELECTRON AND THE UP AND DOWN QUARKSARE EXAMPLES OF PARTICLES THAT
HAVE A CHARGE:
SOME PARTICLES HAVE AN ELECTRIC CHARGE,
OTHERS DO NOT:
UP QUARKCHARGE =
+⅔
ELECTRONCHARGE = -
1
DOWN QUARK
CHARGE = -⅓
SOME PARTICLES HAVE AN ELECTRIC CHARGE,
OTHERS DO NOT:
THE PHOTON AND THE NEUTRINO ARE EXAMPLES OF PARTICLES THAT
DO NOT HAVE A CHARGE:
PHOTON
CHARGE = 0
NEUTRINO
CHARGE = 0
THE PROTON HAS A NET CHARGE OF +1
DUE TOTHE QUARKS THAT MAKE IT UP
PROTON
CHARGE = +1
⅔ ⅔
⅓
THE NEUTRON HAS A NET CHARGE OF ZERO
DUE TOTHE QUARKS THAT MAKE IT UP
NEUTRON
CHARGE = 0
PROTON
CHARGE = +1
⅔ ⅔
⅓ ⅓
⅓⅔
THE PROTON HAS A NET CHARGE OF +1
DUE TOTHE QUARKS THAT MAKE IT UP
YOU ARE PROBABLY ALREADY FAMILIAR WITH SOME OF THE BEHAVIOURS OF CHARGED PARTICLES
YOU ARE PROBABLY ALREADY FAMILIAR WITH SOME OF THE BEHAVIOURS OF CHARGED PARTICLES
FOR EXAMPLE, YOU ARE PROBABLY AWARE THAT LIKE CHARGES
for example, two negative charges
YOU ARE PROBABLY ALREADY FAMILIAR WITH SOME OF THE BEHAVIOURS OF CHARGED PARTICLES
FOR EXAMPLE, YOU ARE PROBABLY AWARE THAT LIKE CHARGES
for example, two negative charges
−− −−
YOU ARE PROBABLY ALREADY FAMILIAR WITH SOME OF THE BEHAVIOURS OF CHARGED PARTICLES
FOR EXAMPLE, YOU ARE PROBABLY AWARE THAT LIKE CHARGES
for example, two negative charges
−− −−
YOU ARE PROBABLY ALREADY FAMILIAR WITH SOME OF THE BEHAVIOURS OF CHARGED PARTICLES
FOR EXAMPLE, YOU ARE PROBABLY AWARE THAT LIKE CHARGES
for example, two negative charges
−− −−
will REPEL each other
YOU ARE PROBABLY ALREADY FAMILIAR WITH SOME OF THE BEHAVIOURS OF CHARGED PARTICLES
AND THAT, OPPOSITE CHARGES
−−++
YOU ARE PROBABLY ALREADY FAMILIAR WITH SOME OF THE BEHAVIOURS OF CHARGED PARTICLES
AND THAT, OPPOSITE CHARGES
--++
YOU ARE PROBABLY ALREADY FAMILIAR WITH SOME OF THE BEHAVIOURS OF CHARGED PARTICLES
AND THAT, OPPOSITE CHARGES
will ATTRACT each other
--++
A BEHAVIOUR OF CHARGED PARTICLES THAT YOU MAY NOT BE FAMILIAR WITH
IS WHAT HAPPENS TO THEM IN A MAGNETIC FIELD*
*The concept of FIELDS are useful in explaining so-called “action-at-a-distance” forces. For example, a gravitational field can be used to explain the attractive force of gravity, and an electric field can be used to explain the attraction of opposite charges and the repulsion of like charges. Likewise, magnetic fields can be used to explain why like poles of two magnets repel each other and their opposite poles attract.
You have probably seen how iron filings line themselves up
around a bar magnet:
We say that the iron filings align themselves with the magnetic field
that surrounds the magnet.
To show what happens to charged
particles in a magnetic field,
we take a “horseshoe”
magnet…
S
N
To show what happens to charged
particles in a magnetic field,
we take a “horseshoe”
magnet…
N
S
…and let this box outline the
region where the magnetic field is
concentrated.
N
S
The field has a direction associated with it, as
shown by the arrow. The direction of a magnetic field always points from
the North pole to the South pole of the magnet.
Dire
ction
of m
agne
tic fi
eld
N
S
If we were to send two
charged particles of equal mass into the
magnetic field…
Dire
ction
of m
agne
tic fi
eld
N
S
…one that is negatively charged…
Dire
ction
of m
agne
tic fi
eld
N
S
…and one that is positively charged…
Dire
ction
of m
agne
tic fi
eld
N
S
…we would find thatthe negatively
charged particle would be deflected
in this direction…
Dire
ction
of m
agne
tic fi
eld
N
S
Dire
ction
of m
agne
tic fi
eld
…we would find thatthe negatively
charged particle would be deflected
in this direction…
N
S
Dire
ction
of m
agne
tic fi
eld …and thatthe positively charged
particle would be deflected by
the same amount but
in the opposite direction.
N
S
…and thatthe positively charged
particle would be deflected by
the same amount but
in the opposite direction.
Dire
ction
of m
agne
tic fi
eld
N
S
…and thatthe positively charged
particle would be deflected by
the same amount but
in the opposite direction.
Dire
ction
of m
agne
tic fi
eld
(You should realize that using a magnet in this way could also be used to DETECT that two UNKNOWN particles had the SAME mass but OPPOSITE charge).