Science 7–10 · Year 10
Spectral fingerprints: hydrogen lines through a diffraction grating, and redshift
Science understanding: Earth and space sciences (ACARA Year 10 origin of the universe; NSW Stage 5 focus area: Waves and motion)
Teacher-led demonstration
A teacher carries out this activity as a demonstration. Its materials, steps, variables, misconceptions and sources are not published on the open web, and neither is any result, control or note that states a number or an amount: tutors and administrators read them on the learning platform, with the safety card first. The idea, the hazards and the curriculum references are below.
Open the procedure on the learning platform (tutor or administrator sign-in)
School laboratory, not for home
In a school laboratory, with a teacher supervising, under the school's risk assessment. Not for home.
This site has no interactive model of its own. Where a step or a material names a Concept Studio model, simulation or tool, it has not been built; an external simulation a step names (for example PhET) is not part of this site.
The idea
Each element gives out and absorbs light only at its own set of wavelengths, so the lines in a galaxy's light identify its elements, and the same pattern shifted to longer wavelengths measures how fast the galaxy is moving away.
Safety card
Setting: In a school laboratory, with a teacher supervising, under the school's risk assessment. Not for home.
Hazards
- high-voltage power supply for the spectrum tubes
- tubes become hot after a few minutes
- looking at the Sun, directly or through any optical device, damages the eye
Controls
- only the teacher connects, switches and changes tubes, with the supply switched off and unplugged before a tube is changed
- tubes allowed to cool and handled with a cloth
- daylight is viewed only as light reflected from white card or sky well away from the Sun
Note
It states a number or an amount, which may be part of the method, so it is shown with the method to tutors and administrators on the learning platform.
What you should see
It states a number or an amount, which may be part of the method, so it is shown with the method to tutors and administrators on the learning platform.
Curriculum references
The NSW syllabus outcomes and Australian Curriculum v9 codes this activity supports. They are references, not a verified or complete curriculum alignment.
- Science 7-10 Syllabus (2023), NSW Education Standards Authority (implemented from 2026; codes read at curriculum.nsw.edu.au on 22 and 23 September 2026)SC5-WAM-01SC5-WS-01SC5-WS-04
- Australian Curriculum v9AC9S10U03AC9S10H02AC9S10I03AC9S10I05