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.
Answer:
Alburt Bandura
Explanation:
Rosalind has learned to be impulsive and seldom waits for her turn when playing with other children, this trait she has learned from her father, who is also an impulsive man.
The theorist who would most likely suggest that Rosalind has learned to be impulsive from watching her father is Alburt Bandura. Alburt in his famous Bebo Doll experiment confirmed that children learn from the adults behavior in their life.
Answer: True
Explanation:
Atomic number is defined as the number of protons or the number of electrons that are present in an electrically neutral atom.
Atomic number = Number of protons = number of electrons = 2
Electronic configuration represents the total number of electrons that a neutral element contains. We add all the superscripts to know the number of electrons in an atom.
The electronic configuration will be 
As its duplet is already complete and it has noble gas configuration , it is stable with 2 valence electrons.
A. Internal. Most cars use that type of set up because it's more efficient, you can find more about it on this website, https://auto.howstuffworks.com/did-cars-ever-have-external-combustion-engines.htm
:)
~ Ria
