You're viewing 1 free preview question for Physics HL — subscribe to unlock 98 more, plus the Full Question Bank, Mock Papers & Worksheets.Upgrade

Structure of the Atom · Paper 2 — Free Physics HL Practice Questions

1MasterySAQ-SAtomic models (Bohr, quantum model)5 marksPaper 2~8 min
A student investigates the photoelectric effect using a sodium metal surface. The work function of sodium is ϕ=1.80 eV\phi = 1.80\,\text{eV}. She illuminates the surface with light from a hydrogen discharge lamp emitting photons from the n=3n = 3 to n=2n = 2 transition. En=−13.6n2 eV,Kmax=hf−ϕ,1 eV=1.60×10−19 J,h=6.63×10−34 J sE_n = -\frac{13.6}{n^2}\,\text{eV}, \quad K_{\text{max}} = hf - \phi, \quad 1\,\text{eV} = 1.60 \times 10^{-19}\,\text{J}, \quad h = 6.63 \times 10^{-34}\,\text{J\,s}
(a)
State what is meant by the ground state in the Bohr model of the atom. [1 mark]
(b)
Calculate the maximum kinetic energy, in eV, of photoelectrons ejected from the sodium surface when illuminated by the n=3n = 3 to n=2n = 2 photons. [2 marks]
(c)
The student replaces the lamp with one emitting photons from the n=4n = 4 to n=3n = 3 transition in hydrogen. Deduce, with a calculation, whether the photoelectric effect occurs for this transition, and explain why the result differs from that in (b). [2 marks]
diagram

Solutions

Questions 2-99

Unlock these questions with Premium

Sign Up →

That's every free question here — 1 of 99.

+98 more questions, plus Mock Papers & Worksheets, are waiting in Premium.

Upgrade