IB Physics HL E.1 Structure of the atom questions

Exam-style multiple choice and written questions with full markschemes. Check multiple choice answers straight away, or type, photograph or draw a written answer and get it marked.

Type
Multiple choiceWritten
Difficulty
EasyMediumHard

Question 1

Paper 2Medium7 marks

A gas is examined using an emission spectrum and an absorption spectrum. The absorption spectrum is recorded after continuous light passes through a cooler sample of the same gas. Figure 1 shows measured relative intensities for both spectra.

For calculations, use h=6.63×10−34 J sh=6.63\times10^{-34}\,\text{J s} and c=3.00×108 m s−1c=3.00\times10^8\,\text{m s}^{-1}

Emission spectrumAbsorption spectrum1.00.90.80.70.60.50.40.30.20.10.01.00.90.80.70.60.50.40.30.20.10.0400450500550600650670Relative emissionintensity /arbitrary unitsRelative absorptionintensity /arbitrary unitswavelength / nm
(a)

Read Figure 1 to state the wavelengths of the shortest- and longest-wavelength emission lines. Give your answers in nm.

[2]
(b)

Determine the energy of a photon in the longest-wavelength emission line. Give your answer in J.

[2]
(c)

Explain what the matching emission and absorption line positions indicate about atomic energy levels.

[2]
(d)

A nucleus of the element contains 12 protons and 13 neutrons. Write its nuclear notation, using XX for the chemical symbol.

[1]

Question 2

Paper 2Hard10 marks

A gas is studied using an emission spectrum and an absorption spectrum. For the absorption measurement, the atoms are initially in their lowest energy state. Figure 1 shows the resolved line positions; each line-centre wavelength has an uncertainty of ±2 nm\pm 2\ \text{nm}

Assume each line corresponds to a photon transition. Take the lowest atomic energy to be 0 eV0\ \text{eV} and use hc=1240 eV nmhc=1240\ \text{eV nm}

Relative intensityEmission00.51415 nm620 nm1240 nmRelative intensityAbsorption00.51415 nm1240 nm3504004505005506006507007508008509009501000105011001150120012501300Wavelength / nm
(a)

State the feature of the emission spectrum that provides evidence for discrete atomic energy levels.

[1]
(b)

Calculate the energy of a photon corresponding to the emission line at 415 nm415\ \text{nm}

[2]
(c)

Calculate the energy gap corresponding to the absorption line at 1240 nm1240\ \text{nm}

[1]
(d)

Using the results from (b) and (c) and the information in Figure 1, determine the minimum number of energy levels needed to account for all the displayed lines. Draw an energy-level diagram, with levels labelled relative to the lowest energy state, and show the transitions corresponding to every displayed emission and absorption line.

[4]
(e)

Explain why the absence of a 620 nm620\ \text{nm} absorption line does not contradict the 620 nm620\ \text{nm} emission line. State the initial state required for absorption of a 620 nm620\ \text{nm} photon.

[2]

The best questions are still waiting

Unlock every question in this topic, then type, photograph or draw your answer and have it marked against the markscheme. Find out where you are dropping marks.

Unlock all questionsCompare Student and Student Plus