Physics 11–12 · Year 12
Spectra from discharge tubes, an incandescent filament and reflected sunlight with a hand spectroscope (syllabus practical)
Module 7: The Nature of Light (Electromagnetic Spectrum)
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.
The idea
Hot dense sources give a continuous spectrum, low-pressure gases energised by an electric discharge give bright lines unique to each element, and the Sun shows dark absorption lines on a continuous background.
Safety card
Setting: In a school laboratory, with a teacher supervising, under the school's risk assessment. Not for home.
Hazards
- spectrum-tube supply at several kilovolts
- hot tubes
- ultraviolet from mercury tubes
- looking towards the Sun
Controls
- teacher changes tubes with the supply off and cooled
- view mercury through the spectroscope only and briefly
- view reflected light from a card, never the Sun
Note
High-voltage supplies: teacher-only operation with a current-limited EHT supply, and record the activity in RiskAssess (https://www.riskassess.com.au/); Science ASSIST risk management sheet https://asta.edu.au/resource/ais-risk-management-and-risk-assessment/.
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.
- Physics Stage 6 Syllabus (2017), current: Year 11 until the end of 2026, Year 12 until Term 3 2027PH12-14PH12-15PH11/12-3PH11/12-7
- Physics 11-12 Syllabus (2025), not yet taught: Year 11 from Term 1 2027, Year 12 from Term 4 2027, first HSC examination 2028PY-12-04PY-12WS-03
- Australian Curriculum v9No Australian Curriculum v9 code is listed.