ESS (IBDP) 1.2 Systems and models unit of work

Full lessons for IB ESS topic 1: ready to pick up and teach - no extra planning needed.
Covers:

• A systems approach should be taken for all the topics covered in the
ESS course.
• These interactions produce the emergent properties of the system.
• The concept of a system can be applied at a range of scales.
• A system is comprised of storages and flows.
• The flows provide inputs and outputs of energy and matter.
• The flows are processes that may be either transfers (a change in location)
or transformations (a change in the chemical nature, a change in state or a
change in energy).
• In system diagrams, storages are usually represented as rectangular boxes
and flows as arrows, with the direction of each arrow indicating the direction
of each flow. The size of the boxes and the arrows may be representative of
the size/magnitude of the storage or flow.
• An open system exchanges both energy and matter across its boundary
while a closed system exchanges only energy across its boundary.
• An isolated system is a hypothetical concept in which neither energy nor
matter is exchanged across the boundary.
• Ecosystems are open systems; closed systems only exist experimentally,
although the global geochemical cycles approximate to closed systems.