Answer: a) 274.34 nm; b) 1.74 eV c) 1.74 V
Explanation: In order to solve this problem we have to consider the energy balance for the photoelectric effect on tungsten:
h*ν = Ek+W ; where h is the Planck constant, ek the kinetic energy of electrons and W the work funcion of the metal catode.
In order to calculate the cutoff wavelength we have to consider that Ek=0
in this case h*ν=W
(h*c)/λ=4.52 eV
λ= (h*c)/4.52 eV
λ= (1240 eV*nm)/(4.52 eV)=274.34 nm
From this h*ν = Ek+W; we can calculate the kinetic energy for a radiation wavelength of 198 nm
then we have
(h*c)/(λ)-W= Ek
Ek=(1240 eV*nm)/(198 nm)-4.52 eV=1.74 eV
Finally, if we want to stop these electrons we have to applied a stop potental equal to 1.74 V . At this potential the photo-current drop to zero. This potential is lower to the catode, so this acts to slow down the ejected electrons from the catode.
Correct answer is:
<h2>The maximum number of orbits in an atom is <u>Seven.</u></h2><h3>Explanation:</h3>
Every energy level has a limited one orbital including two electrons. The orbits are settled in the sub-levels and there can be further than 1 sub-level as the number of energy levels rises. On energy level 1, there is 1 sub-level and 1 orbital. Energy level 2 can possess 2 sub-levels and 2 orbitals. These remain to develop as you progress from the nucleus of the atom, closing up with an infinite potential number of levels and orbits.
The transfer of energy that occurs when a force is applied over a distance is WORK.
Answer:
wire 66.0 cm long carries a 0.750 A current in the positive direction of an x axis through a magnetic field $$\vec { B } = ( 3.00 m T ) \hat { j } ...
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