Particles

Question 1

Explain the significance of an electron at an energy level of 0eV

Answer 1

this means the atom has been ionised and as been liberated from the atom

Question 2

Where’s the stopping potential on a Graph of I/V

Answer 2

It is the voltage at which the current is 0. The photoelectron with the greatest Ek is stopped by the stopping potential (Ball up a hill analogy)

Question 3

Name key things of this graph + what would happen if the work function increased?

Answer 3

• The gradient represents planck’s constant
• Therefore same gradient
• Work function is proportional t threshold frequency
• Therefore bigger fmin so x-intercept is greater

Question 4

How many transitions are there with 5 energy levels?

Answer 4

5+4+3+2+1 = 15 transitions

Question 5

Stopping potential equation

Answer 5

Ekmax = eVs