Grade 7 Unit C: Curriculum Links | Print |

Unit C: Heat and Temperature
(emphasis on Social and Environmental context)

The production, transfer and transformation of heat energy plays an important role in meeting human needs. In learning about heat, students investigate sources and uses of heat energy and consider the impact of their use on our long-term ability to meet energy needs. In focusing their studies, students explore different applications, investigate the scientific principles involved, and consider questions about the nature of heat. The particle model of matter is introduced to help students explain their observations and understand relationships between heat (Thermal energy) and temperature.

Focusing Questions:
What heat-related technologies do we use to meet human needs, based on what scientific principles?

What implications do these technologies have for sustainable use of resources?

Key Concepts

Note: The terms heat energy and thermal energy may both be used in this unit. Heat energy is the more familiar term for younger students and is useful in introducing the topic. The term thermal energy is the preferred scientific term, and should be introduced during the unit to help prepare students for later grades.

STS and Knowledge Outcomes

Students will:
Illustrate and explain how human needs have led to technologies for obtaining and controlling thermal energy, and to increased use of energy resources
investigate and interpret examples of heat related technologies and energy use in the past (e.g., investigate uses of heat for domestic purposes such cooking or home heating, and for industrial processes such as ceramics, metallurgy or use of engines) History of Heat
trace linkages between human purposes and the development of heat-related materials and technologies (e.g., development of hair driers and clothes driers, development of protective clothing such as oven mitts, ski suits, and survival clothing) History of Thermology
identify and explain uses of technological devices and systems to generate, transfer, control or remove thermal energy (e.g., identify needs for devices or systems that will maintain a constant temperature) aquarium heaters
identify examples of personal and societal choices in using energy resources and technology (e.g., identify choices that affect the amount of hot water used in their daily routines, identify choices in how that water is heated) - sustainable choices

Students will:
Describe the nature of thermal energy and its effects on different forms of matter using informal observations, experimental evidence and models

compare heat transmission in different materials (e.g., compare conduction of heat in different substances; compare the absorption of radiant heat by different surfaces)
explain how heat is transmitted by conduction, convection and radiation in solid, liquids and gases
describe the effect of heat on the motion of particles, and explain changes of state using the particle model of matter (states of matter)(Particle Theory)
distinguish between heat and temperature, and explain temperature using the concept of kinetic energy and the particle model of matter
investigate and describe the effect of heating and cooling on the volume of different materials, and identify applications of these effects (e.g., use of expansion joints on bridges and railway tracks to accommodate thermal expansion)

Students will:
Apply an understanding of heat and temperature in interpreting natural phenomena and technological devices

describe ways in which thermal energy is produced naturally (e.g., describe examples such as solar radiation, combustion of fuels, living things, geothermal sources and composting)
describe examples of passive and active solar heating (solar), and explain the principles that underlie them (e.g., design of homes to maximize use of winter sunshine)
compare and evaluate materials and designs that maximize or minimize heat energy transfer (e.g., design and build a device that minimizes energy transfer such as an insulated container for hot drinks; evaluate different window coatings for use in a model home)
explain the operation of technological devices and systems that respond to temperature change (e.g., thermometers, bimetallic strips, thermostatically controlled heating systems)
describe and interpret the function of household devices and systems for generating, transferring, controlling or removing thermal energy (e.g., describe in general terms the operation of heaters, furnaces, refrigerators and air conditioning devices)
investigate and describe practical problems in controlling and using thermal energy (e.g., heat losses, excess energy consumption, damage to materials caused by uneven heating risk of fire)

Students will:
Analyze issues related to the selection and use of thermal technologies, and explain decisions in terms of advantages and disadvantages for sustainability

identify and evaluate different sources of heat, and the environmental impacts of their use (e.g., identify advantages and disadvantages of fossil fuel use; compare use of renewable and non-renewable sources in different applications) Fuel Cells Renewable Energy Resources
compare the energy consumption of alternate technologies for heat production and use, and identify related questions and issues (e.g., compare the energy required in alternate cooking technologies such as electric stoves, gas stoves, microwave ovens and solar cookers; identify issues regarding safety of fuels, and hot surfaces, and combustion products (solar hot water heater))
identify positive and negative consequences of energy uses, and describe examples of energy conservation in their home or community