1. To which group of animals does a frog belong ?

2. About 20cm of magnesium ribbon is chopped up into 1cm lengths and placed in a crucible which is then weighed along with its lid.

The crucible is heated strongly and the lid gently raised avery few seconds.
When the lid was raised a bright glow was seen to spread through the mixture

When the reaction is over the crucible + contents + lid are all re-weighed.
A white ash remains in the crucible.

These are his results:

• Mass of empty crucible + lid  = 51.2g
• Mass of crucible + lid + magnesium (before heating) = 54.3g
• Mass of crucible + lid + contents (after heating) = 54.7g

 

What evidence is there that a chemical change is taking place?
(read all options before answering) 

3. What type of animal is an omnivore?

4. Pick a chemical that reacts with water

5. When clothes dry the water is

6. What is the unit of pressure?

7. What is NOT true about air

8. Something has kinetic energy when....

9. What are microbes?

10. A spring is 10cm long.
When 3 newtons are hung from it the sprng becomes 16cm.

What extension is caused by the load of 3N?