Answer:
Explanation:
λ = hc/¢
Where
h = the Plank constant 6.63 x 10-34 Is
C = 3.0×10^8
¢= 1.96eV
= (6.63×10^-34Js)×(3×10^8)÷( 1.96eV) × 1eV/1.6×10^-19J
= (1.989×10^-25)÷( 1.96eV)×1eV/1.6×10^-19J
= 6.342×10^-7m
B) maximum kinetic energy
= K=hf−ϕ ........1
ϕ = hc
Where
h = constant 6.63 x 10^-34Js
ϕ= 1.96eV
Recall
λ =425×10^-9m
f = frequency in Hz
f = c / λ
C = 3.0×10^8
f = 3.0×10^8 / 425×10^-9m
f = 0.000705Hz
From equation 1
K = (6.63 x 10^-34Js×0.000705Hz )- 6.63 x 10^-34Js×3.0×10^8
= 4.68×10^-37 - 1.989×10^-25
= - 1.98×10^-25J
