In: Physics
1- Answer the following questions:
i) In Rutherford's experiments the fact that some of the alpha particles were deflected at large angles indicated that Select one:
a. Charge is quantized
b. The charge of the nucleus is positively charged
c. Most of the mass is concentrated in the centre of the atom
d. Positive charge is smeared out throughout the entire volume of the atom
e. Momentum is not conserved within the nucleus
II) If a photoelectric material has a work function ϕϕ, the threshold wavelength for the material is given by Select one:
a. hf b. ϕEϕE. c. hcϕhcϕ. d. ϕhcϕhc e. ϕhf
III) Why does the hydrogen atom produce a large number of lines, whereas it only has one electron? Select one:
a. Ordinary hydrogen doesn't produce lines: it is only solid hydrogen which has many electrons
b. The electron can exist in various energy levels: it is jumping from one to another that gives the spectral lines
c. Due to quantum mechanics, the electron can be in many places at the same time
2- What is the wavelength, in nanometres, of a photon with 1.25 eV energy?
3- A 22.1 eV photon is incident on a metal surface with a work function of 2.22 eV. What is the maximum kinetic energy of the emitted photoelectron in eV.?