Scheme of Work

The scheme of work below is related to existing national curricula e.g.UK National Curriculum.


Practical activity will be supported by a series of short videos, rather than text recipes. Apart from being more explicit, videos serve a dual function of providing evidence of the use of instruments, and of providing a resource for both learners and teachers.
This activity focuses on the measurement of pressure and its change with temperature, rather than the traditional change in volume. Pressure changes have a certain obviousness of tangible feel about them.This matches Amontons' historical work, but also more easily leads into a sub-microscopic cause and effect explanation. The pressure gauge equipment may not be readily available in schools but an alternative liquid manometer arrangement can easily be set up. The video of the alternative arrangement can then be used for a discussion of the value of instruments.
The experiment consists of attaching a pressure gauge to an otherwise closed flask with air in it. A video will be made available for training, and as a resource for students who have missed the lesson.
The pressure increases when the air is heated, and can be felt. The use of a gauge introduces instruments. A manometer can be substituted for a mechanical pressure gauge and will provide a useful introduction to instrumentation.

The push of the particles against an external surface is a powerful explanation here.

Children's Ideas:
Novick & Nussbaum (MSSS 93) found that 13-14 years old children were uncertain about particulate and continuous matter in liquids and, possibly, in gases. Séré (MSSS 152) found that 85% of 11-13 years old could describe squashing air in a ball but 63% referred to the balance of inside and outside pressure. Séré also found these children associating pressure with moving air and not static air.
Guillaume, Amontons Biography and another Amontons Biography
Amontons used approximate thermometers but came up with the idea of an absolute zero.
This activity links a macroscopic observation with a causal sub-microscopic explanation. The notion of cause and effect is an important philosophical matter. Wikipedia here
A second major philosophical area is the relation between measurement and concept development. While there is no intention to pursue this far in this short introduction, the measurement of a thermometric property (expansion of a liquid, or increase in pressure of a gas) and understanding the concept (temperature in this case) was not obviously related in history. This section is as much devoted to developing a teacher's appreciation of this problem at a higher level as showing young learners the problem of determining a fixed calibration point using real instruments.
Thermal expansion of fluids (liquids and solids)
The next associated lesson is on volume expansion of gases. It parallels Gay-Lussac's historical work. He noted that the thermal expansion of gases is regular and the same for all gases, but that of solids and liquids is not.
We can have two activities: a flask fitted with a flexible tube, bubbling into a 100 mL measuring cylinder in a tub of water. Immersing the flask in a tub of warm water will enable the volume change to be measured. The second activity uses a balloon stretched over the mouth of a flask. the flask is placed in a tub of warm water. This activity is not quantitative and provides a good contrast with the (approximately) quantitative prior experiment.

The second part focuses on expansion of liquids as a prelude to the next section.
Flasks containing coloured water fitted with a stopper and glass tube can be placed into ice cold water (ice and water) and then into water at different temperatures (water baths) to calibrate.
Thermal expansion of gases (is regular if measured). Refer to original papers and secondary evidence for other gases.
Expansion of liquids is much smaller than for gases and different for different liquids. Refer to original papers and secondary evidence or here for liquids.

The idea of volume change for gases is complex since there is always external air pressure to take into account, and this is not always obvious!

Children's Ideas:
This aspect of conceptual learning has not been well studied. Unpublished work by Oversby and Marks with 17 years old students in Malta suggested that thermal expansion of solids is through particles bumping against each other but no work appears to have been done on thermal expansion of liquids. Oversby (unpublished) also found similar ideas with adult pre-service teacher education students.
Challenge to scientists accepted idea of vibrating atoms
Gay-Lussac's biography, including his work on expansion of gases with temperature, and referring to the work of Charles, in French. The first paragraph of his memoir concluded with the hope that 'we are perhaps not far removed from the time when we shall be able to submit the bulk of chemical phenomena to calculation' (Crosland MP (1978) Gay-Lussac Scientist and Bourgeois p 54 Cambridge University Press, Cambridge)

Fenby's paper Heat: Its Measurement from Galileo to Lavoisier
Nature of 'discovery' i.e. who is credited (and in which culture) with the act of discovery?

Nature of measurement and primary standards. Determination of the boiling point of water even after allowing for external pressure changes) was a difficult process. This exercise aims to start an understanding of the practical difficulty of calibration of real thermometers, using real instruments.
Comparison of different kinds of thermometers. Almost no systematic studies have been carried out with a variety of thermometers, in the light of instruments being used to develop data collection in school science.
A lesson plan based on mercury-in-glass and glass clinical thermometers, thermocouples, resistance thermometers, bimetallic strip, and thermistors The mode of operation is described but no indication of precision or accuracy.
A wider range is given by Wikipedia
An excellent history of temperature and thermometry, written in reasonably accessible language for older teenagers
Another published history of thermometry more suitable for teachers.
Practical thermometers for measuring body temperatures are explained in the HowStuffWorks site. The explanations seem suitable for older teenagers.
Various macroscopic features (volume, length, resistance, potential difference of a junction between two metals) change with changing temperature and can be used in thermometry.
Explanations of other thermometers tend to be at the macroscopic level.
Children's Ideas:
Appleton (MSSS 140) found, in a small sample, 8-11 years old children did not recognise a thermometer in Australia.
Inventors of different thermometers
The relationship between data and explanation is one to be explored here.


The first session deals with the earliest historical ideas about heat through fire.
Exploration of mass change of burning of a fuel (wood) with burning magnesium or copper.
ICT link between respiration and burning
Oxygen in air.
Air as a mixture of gases.
Molecules of oxygen, sucrose or glucose. carbon dioxide and water.
Children's Ideas:
11-12 year old children know that air is needed for burning, but not its function (MSSS 87, several studies). Meheut and others (MSSS 87), with French 11-12 year old learners, found that they did not appreciate the chemical nature of the process. Pfundt (MSSS 87) found that 8-13 year old learners confused evaporation and burning in the case of alcohol. various studies (MSSS 87) also noted learners uncertainty about mass changes on burning with 15 year old learners.
Wikipedia - heat
The history of heat began when early man made fire and tried to make sense of what fire was. The concept of fuel is embedded in the concept of fire. In the 1718, Stahl characterised phlogiston as something that is set free on burning. Another biography of Stahl. Lomonosov in 1753 concluded that phlogiston did not exist by weighing heated metals. Lavoisier's discovery of hydrogen in 1783 put paid to the phlogiston concept for many scientists. Caloric as a substance explained much about heat transfer. Joule's work (1843) on the mechanical equivalent of heat linked work to heat.
Avoidance of whiggishness
Phlogiston theory allowed chemists to bring explanation of apparently different phenomena into a coherent structure: combustion, metabolism and formation of rust. The recognition of the relation between combustion and metabolism was a forerunner of the recognition that the metabolism of living creatures and combustion can be understood in terms of fundamentally related chemical processes
The second experiment is a re-enactment of heat measurement through the use of a mock up of an ice calorimeter. In the UK, children aged 11-14 have to understand the relationship between burning and respiration.
Latent heat
Structure of solid and liquid water
Children's Ideas:
As noted above, these concepts are not so easily established. Erickson (MSSS 138) showed that heat is seen by young learners as a kind of air, paralleling the historical position. Engel lough and Driver (MSSS 138) found that 'cold' was seen as opposite of 'heat' as a counter concept.
Calorimeters including ice calorimeter

The third session looks at the passage of heat from a hot block of metal to water in an insulated beaker. Learners will be asked to consider explaining it in terms of caloric.
Heat and thermal energy
Heat and particle vibration
Structure of solids and liquids.
Children's Ideas:
As noted above, these concepts are not so easily established. Erickson (MSSS 138) showed that heat is seen by young learners as a kind of air, paralleling the historical position. Engel lough and Driver (MSSS 138) found that 'cold' was seen as opposite of 'heat' as a counter concept.
Caloric as a substance explained much about heat transfer.