Answer:
Kinetic Energy = 6.51x10^-19 J (3 s.f)
Explanation:
frequency = 1.50×1015 s^-1
Kinetic Energy = ?
Kinetic Energy = ħf - ф
h = plank's constant = 6.626x10^-34 Js
hf = 6.626x10^-34 * 1.50×10^15 = 9.939x10^-19 J
Work function, ф = 2.1 eV = 3.3642x10^-19 J (upon conversion to joules
Kinetic energy = 9.939x10^-19 J - 3.3642x10^-19 J
Kinetic Energy = 6.511x10^-19 J
Kinetic Energy = 6.51x10^-19 J (3 s.f)