Across
- 2. A _____________change is reversible and no new substances are made.
- 4. A substance that makes your skin itch or swell up a little. Hazard symbol shows a cross.
- 6. If an acid has a large number of solute particles per unit volume then it is a c___________________ acid.
- 8. Chemical changes cannot be undone. We say that they are i________________
- 9. Substance made when an acid and alkali react. Examples are sodium chloride and copper sulfate.
- 11. A soluble base.
- 12. A substance that is made in a chemical reaction.
- 13. A starting substance in a chemical reaction.
Down
- 1. A positive test for this gas is a squeaky pop when tested with a lit splint.
- 3. A table of all the elements, in which elements with similar properties are grouped together.
- 5. Acids can eat through materials. We say they are ___________________
- 7. A substance that neutralises an acid – those that dissolve in water are called alkalis.
- 8. Substances used to identify whether a substance is acidic, alkaline or neutral.
- 10. A solution with a pH value less than 7.
- 14. Brushing your teeth is an example of a __________________ reaction.