1. 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 reaction is over a white ash could be seen in the crucible.
The crucible + ash + lid are all re-weighed

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 is the name of the white ash that remains in the crucible after the experiment 

2. Pick an alkaline oxide from the list

3. What would be the effect on a habitat if all the herbivores suddenly died out

4. What gas is used up by plants during photosynthesis

5. Which of the following produces a permanent chemical change

6.  

Which of the lamps in the diagram will be on?

7. You have four substances which you label A, B, C and D.
One is a mixture, one a metallic element one a non-metallic element and one a compound.

They have the following properties:

A	A yellow, crumbly solid that burns to form a single colourless gas which turns universal indicator red
B	A grey, malleable solid that burns to form a single white alkaline oxide
C	A colourless liquid. The liquid is warmed in a shallow dish and after a few minutes a white residue is seen
D	A green solid that decomposes when heated to form a colourless gas and leave a black powder

Which of the substances is likely to be a non-metallic element ?

8. The diagram shows a log supported at its centre.
Peter is 1.5m from the centre and John is 2.5m from the centre.
Does the log balance, and if not which side goes down?

9. A change of electrical energy into kinetic (speed) energy could be produced by

10. Put the following processes into the correct order if you wished to obtain pure salt from rock salt