The greater the work function for a metal,
A) the greater the speed of the ejected electron
B) the smaller the speed of the ejected electron
C) the more electrons are ejected
D) the lower the threshold frequency
E) none of the above
E) none of the above
The correct answer is E) none of the above.
To understand why, we need to have a basic understanding of the work function of a metal. The work function is the minimum amount of energy required to remove an electron from the surface of a metal. It is often represented by the symbol Φ.
Now let's analyze the answer choices:
A) The greater the work function, the greater the energy required to remove the electron from the metal. This means that the electron would have a lower kinetic energy and, therefore, a lower speed once it is ejected. Therefore, this choice is incorrect.
B) Similarly to option A, the greater the work function, the greater the energy required to remove the electron. This would result in a lower speed of the ejected electron. So, this choice is also incorrect.
C) The work function does not affect the number of electrons ejected. It only determines the energy required to remove each individual electron. Therefore, this choice is incorrect.
D) The threshold frequency is related to the energy required to remove an electron, but it is not directly dependent on the work function. The threshold frequency is the minimum frequency of incident light needed to cause the ejection of electrons from a metal surface through the photoelectric effect. The relationship between the work function and the threshold frequency is given by the equation:
hf = Φ + KE
where h is Planck's constant, f is the frequency of the incident light, Φ is the work function, and KE is the kinetic energy of the ejected electron. From this equation, it is clear that the work function (Φ) and the threshold frequency (f) are independent. So, this choice is also incorrect.
Therefore, the correct answer is E) none of the above.