Science 7–10 · Year 10
The greenhouse bottle demonstration: testing a popular claim with an argon control
Science understanding: Earth and space sciences (NSW Stage 5 focus areas Environmental sustainability and Data science 2)
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
Two sealed bottles under a lamp, one holding carbon dioxide, usually give the result the greenhouse effect predicts, but Wagoner, Liu and Tobin (2010) showed that such a result can come from heat transfer rather than infrared absorption, and that argon, as dense but absorbing no infrared, is the control that separates the two, so the demonstration has to be evaluated rather than trusted.
Safety card
Setting: In a school laboratory, with a teacher supervising, under the school's risk assessment. Not for home.
Hazards
- compressed-gas cylinder under high pressure (argon or carbon dioxide)
- argon and carbon dioxide displace oxygen if released in quantity in a closed space
- hot lamp: an infrared heat globe runs hotter than a lighting globe
- hydrochloric acid 1 mol/L if carbon dioxide is generated
Controls
At least one of them states a number or an amount, which may be part of the method, so the controls are shown with the method to tutors and administrators on the learning platform.
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-ENV-01SC5-DA2-01SC5-WS-03SC5-WS-04SC5-WS-08
- Australian Curriculum v9AC9S10U04AC9S10H01AC9S10I06AC9S10I07