boratory reference has three dark absorption lines. In the spectra for galaxies P, Q, R, and S, these dark lines are shifted towards the red end (longer wavelengths) of the spectrum. Galaxy S shows the greatest shift to the right, followed by Galaxy R, then Galaxy Q, and Galaxy P has the smallest shift.](https://assets.mathsgenie.co.uk/aqa-qb/64404b41-515f-484c-ac6f-e69fad0119dd.png)","difficulty":5,"difficultyBand":"medium","totalMarks":3,"sourceTitle":null,"calculatorUse":null,"parts":[{"id":"c6c446a0-a2e7-43af-810c-b470deffe6d1","label":null,"content":"Explain, using the diagram, which galaxy is furthest away from Earth.","markscheme":"- Identifies **Galaxy S** as the furthest galaxy A1\n- Explains that **Galaxy S** has the largest redshift because its spectral lines are shifted the furthest towards the longer-wavelength (red) end of the spectrum M1\n- Explains that a larger redshift indicates a greater recessional velocity, and according to Hubble's Law ($v = H_0 d$), velocity is directly proportional to distance, so the fastest-moving galaxy is the furthest away M1","marks":3,"order":0,"markingRubric":null,"explanation":{"methods":[{"id":"compare_redshift","label":"Compare the redshifts","steps":[{"type":"text","order":1,"title":"Compare the spectral lines","content":"Match each of the three dark absorption lines with the corresponding line in the laboratory reference, then compare how far right they have moved. Right means a longer wavelength, towards the red end of the spectrum.\n\nGalaxy S has all three matching lines shifted furthest to the right, so it has the **largest redshift**. This observation earns the first M1.","highlights":[{"text":"using the diagram, which galaxy is furthest away from Earth.","location":"specification"}]},{"type":"hyper_latex","block":{"nodes":[{"latex":"\\text{larger redshift}\\ \\longrightarrow\\ \\text{greater recessional velocity }\\htmlData{anchor=v}{v}"},{"latex":"\\htmlData{anchor=law-v}{v}=H_0\\htmlData{anchor=law-d}{d}"},{"latex":"\\text{greater recessional velocity }v\\ \\longrightarrow\\ \\text{greater distance }d"},{"text":"Therefore, Galaxy S is furthest from Earth."}],"highlights":[{"color":"amber","style":"box","anchor":"law-v"},{"color":"sky","style":"box","anchor":"law-d"}]},"order":2,"title":"Link redshift to distance","description":"A larger redshift means that the galaxy is moving away faster. Hubble's Law shows that greater recessional velocity means greater distance. This earns the final M1; therefore, Galaxy S is furthest from Earth, earning A1."}]}],"generatedAt":"2026-07-22T08:28:45.051Z","modelVersion":"gpt-5.6-terra+diagrams-1","explanationVersion":"v3"},"options":[]}],"options":[],"explanation":null,"firstAttemptFullMarks":null},{"id":"ddf0d47e-4277-4adf-beb8-38ec44b314da","revisionId":"1011310b-da1a-45b6-bfb0-adf5946c9cb4","questionNumber":null,"questionType":"LA","specification":"Figure 3 shows the absorption spectra of a specific element obtained from a laboratory reference source and from four distant galaxies (P, Q, R, and S).\n\nAll spectra are drawn to the same scale and aligned vertically.\n\n![Absorption spectra of a laboratory reference source and four galaxies labeled P, Q, R, and S.](https://assets.mathsgenie.co.uk/aqa-qb/6e31381e-93a0-4dd0-8eed-9491836ed423.png)","difficulty":6,"difficultyBand":"medium","totalMarks":3,"sourceTitle":null,"calculatorUse":null,"parts":[{"id":"e5743889-e103-4c6f-9761-648d8f324fc9","label":null,"content":"Explain, using the information in Figure 3, which galaxy is the furthest distance from Earth.","markscheme":"- Identifies the correct galaxy as **Galaxy Q** A1\n- States that Galaxy Q's spectral lines are shifted the furthest towards the red/longer wavelength end of the spectrum (it has the largest redshift) M1\n- Explains that a greater redshift indicates a higher recession velocity, and since velocity is proportional to distance (or more distant galaxies recede faster), Galaxy Q must be at the furthest distance M1","marks":3

The Big Bang, red-shift and the expanding Universe

Question 22

The Big Bang, red-shift and the expanding Universe Questions

The Big Bang, red-shift and the expanding Universe

Question 22

The Big Bang, red-shift and the expanding Universe Questions