Primary Science Matters - 2010

1. Primary Science Matters - 2010 Day 1 – Session 3 Good Science Lessons

2. Primary Science Matters What are some of the common features of good science lessons ?

3. Children's common alternative conceptions Physical States of Matter • Students have particular problems with recognising the existence of gases as a physical state of matter because most gases are invisible • The word ‘gas’ is used to describe a flammable fuel that is burnt to generate heat in stoves. • A common belief encouraged by the invisibility of gases is they are weightless and do not occupy space . Confusion can originate when students are regularly told that containers and jars with nothing in them are empty but are then expected to grasp that although empty, they really contain air. • Students freely associate liquids with water or assume they all contain some water because they are a liquid. • Freezing of all materials only takes place at cold temperatures such as in the refrigerator or freezer

4. Children's common alternative conceptions Forces and Motion • Pushes and pulls are associated only with living things and to a lesser extent with mechanical machines that cause motion, such as cars pulling boats or bulldozers pushing piles of soil. • A moving object is thought to ‘contain’ or ‘have’ force. Some students think such a force keeps objects moving; and that objects slow down and stop because this force is gradually used up. • Students’ everyday experience of moving objects is that they need a constant push to keep them moving. • Friction is not itself seen as involving forces and nor is it seen as being present when things are not moving (for example, acting on a child who sits stationary halfway down a slide).

5. Children's common alternative conceptions Living things • Students think various lifecycle stages of a butterfly are not alive (the eggs and immobile pupae), whereas a caterpillar and butterfly can move and are therefore considered to be alive. • The common usage of the word ‘plant’ generally refers to a small, low growing shrub and ‘animal to four footed mammals not allowed in butchers shops or on freeways

6. Floating & Sinking – Diagrams can be helpful • Why do things float? (or sometimes sink?)

7. Forces at work for floating & sinking Object Liquid

8. Forces at work for floating & sinking

9. Forces at work for floating & sinking

10. Forces at work for floating & sinking Close up view

11. Forces at work for floating & sinking Close up view

12. Forces at work for floating & sinking Close up view

13. Forces at work for floating & sinking Close up view

14. Forces at work for floating & sinking Close up view

15. Forces at work for floating & sinking Remove most of the mass Weight force is now reduced

16. Forces at work for floating & sinking Object rises until the buoyancy forces balance the smaller weight force - the object floats!