Threshold frequency is the Minimum frequency of Light that when incident on a material will eject a photoelectron.
The minimum amount of energy required to eject electron is given as:-
E(work function) = E(energy of incident light) - E(kinetic energy of photoelectron)
E(work function) = 8.4 × 10-17 J - 6.4 × 10-17 J = 2.0 × 10-17 J
Energy = h✓
✓ = frequency
h = Plank's constant = 6.64 × 10-34 J s
Threshold frequency = 2.0 × 10-17 J / 6.63 × 10-34 J s
Threshold frequency = 3.02 × 1016 s-1
when the metal surface was hit with photons with an Question 9 Not yet answered Suppose...
When 289-nm photons are incident on the surface of a metal, electrons are ejected from it and the stopping potential is 2.69 V. Find the energy of incident photons: E,= (4.287 eV. Find the kinetic energy of ejected electrons: K= eV. Find the work function of the metal: p= 1.597 ✓ev. Find the wavelength of the least energetic photon that can induce the photo- electric effect in this metal 2 = 778 nm.
Question 8 (1 point) Electrons will be ejected from the surface of the metal molybdenum (Mo) by photons of 274 nm or less. What is the minimum energy required to ejected an electron from the Mo surface? 07. 25 10-19 J O 7.25 x 10-28 J O 1.82 x 10-31 ] 04.37 % 10% Next Page
Question 3 in heating and cooling, 9 = Not yet answered Select one: ATIC Marked out of 1.00 P Flag question O -ΡΔν • CVAT O m c ΔΤ Question 4 Physical changes occur at constant Not yet answered Marked out of 1.00 Select one: • entropy O time p Flag question temperature O energy A change of temperature of -5°C is equivalent to a temperature change of... Question 5 Not yet answered Marked out of 1.00 P Flag question...
18 Question 4 photons of 525 nm are collected over a period of 2.5 hours. Calculatehow many joules of energy are hitting the detector each second. 4.3 x 10 Not yet answered Select one: Marked out of 0.65 3.00 0.011 Flag question 1.63 -4 1.81 x 10 5 5.4x 10
Question 9 Not yet answered Marked out of 1.0 Flag question Which of the following compounds is an ester? Select one: 0 0 0 O 0 0 Question 10 Not yet answered Marked out of 1.0 P Flag question How many isomers, excluding cyclic compounds and any enantiomers, are possible for C, H, Br? OOO Select one: O a. 12 O b. 11 O c. 14 O d. 9 o e. 13
QUESTION 9 Not yet answered 302 4v w Marked out of 1 Flag question 4v } 50 3v } 20 30 Calculate potential difference between x and y. Select one O a.-4.275V O b. 4.275V O C.-4.527 O d. 4.527V QUESTION 10 The reciprocal of resistance is called Not yet answered Marked out of 1 Select one: P Flag question O a. Capacitance O b. Inductance O c. Conductance O d. Concoctance
Question 9 Not yet answered Marked out of 3.00 p Flag question What is the major product of the reaction below? Br KOtBu, tBuOH 60 °C Select one: a. Ob. O c . O d. OH
Quiz navigation Question 1 A half equation always contains... Not yet answered Marked out of 1.00 Select one: protons Finish attempt... electrons P Flag question Time left 0:04:53 water spectator ions Question 2 In basic solution, what can you always add in order to balance a half-equation? Not yet answered Marked out of 1.00 P Flag question Select one: OH and Nat Hi and H2O O OH' and H20 H* and OH When half equations are balanced against each other,...
Energy is always... Question 4 Not yet answered Marked out of 1.00 P Flag question Select one: o decreasing o lost • conserved o increasing Question 5 When a compound gains energy the process is Not yet answered Marked out of 1.00 Select one: • endothermic P Flag question O hypothermic exothermic hyperthermic o Question 6 Bonus question: heat will pass by conduction and heat will pass by convection and heat will pass by radiation and that's.... Not yet answered...
Question 4 The pH is defined as Not yet answered Marked out of 1.00 P Flag question Select one: 0 -log[H] o 10[++] O 10-[H+] O log[H+] Question 5 If the pol of a solution is 4, what is its pH? Not yet answered Marked out of 1.00 Select one: o 7 O 10 p Flag question