1. Signs of Chemical Reactions
N4 Basics
Signs of Chemical Reactions 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25
Calderglen High School

2. 1. What always happens in a chemical reaction?
answer
A new substance is always formed
Calderglen High School

3. 2. Give examples of signs that a chemical reaction has occured?
answer
Energy change
Permanent colour change
Gas produced (effervescence)
Solid formed in a liquid
Calderglen High School

4. 3. An element is ……… An element is the simplest type of substance.
answer
An element is the simplest type of substance.
It is made up of only 1 type of atom.
Calderglen High School

5. 4. What is a GROUP in the Periodic Table?
answer
A column
Calderglen High School

6. 5. What are the Group 1 elements called?
answer
Alkali metals
Calderglen High School

7. 6. What are the Group 7 elements called?
answer
Halogens
Calderglen High School

8. 7. What are the Group 0 elements called?
answer
Noble gases
Calderglen High School

9. Calderglen High School
8. What are compounds?
answer
Substances made of two or more different types of atom joined together.
Calderglen High School

10. 9. What is the difference between a compound and a mixture?
answer
The atoms of a compound are joined together. The substances in a mixture are NOT joined and can be easily separated.
Calderglen High School

11. Calderglen High School
What element is present in compounds that have names ending in –ate and –ite?
answer
oxygen
Calderglen High School

12. 11. What does -ide at the end of the name of a compound indicate?
answer
IDE means that the compound is made up of the TWO elements
e.g. Sodium chloride has SODIUM and CHORINE
Calderglen High School

13. (a thing that get dissolved)
12. A solute is ……….
answer
(a thing that get dissolved)
A solute is a substance (usually a solid) which dissolves in a solvent to form a solution.
Calderglen High School

14. 13. A solvent is ………… A liquid in which a solute dissolves. answer
Calderglen High School

15. Calderglen High School
14. What is a SOLUTION?
answer
A solution is formed by dissolving a solute (usually a solid) in a solvent (usually a liquid)
Calderglen High School

16. 15. What is an AQUEOUS SOLUTION?
answer
When a substance has been dissolved in WATER
(think of AQUA = water)
Calderglen High School

17. 16. What is meant by a property of a chemical?
answer
A property of a chemical is what it is like or what it can do chemically
Calderglen High School

18. 17. What is the meaning of the words CONCENTRATED and DILUTE?
answer
Concentrated means a large amount of solute in a small volume of solvent.
Dilute means a small amount of solute in a large amount of solvent
Calderglen High School

19. 18. What is a SATURATED solution?
answer
A saturated solution is a solution which cannot dissolve any more solute.
Calderglen High School

20. Calderglen High School
19. Where in the Periodic Table would you find the METALS and the NON-METALS?
answer
Metals are found to the Left Hand Side of the zigzag line; Non-metals to the Right Hand Side of the zig-zag line
Calderglen High School

21. Calderglen High School
20. What are ATOMS?
answer
Atoms are very small, particles which make up every element. They are too small to see.
Calderglen High School

22. Calderglen High School
21. What is a PRECIPITATE?
answer
A precipitate is a solid which is formed when two solutions react together
Calderglen High School

23. 22. What is EFFERVESCENCE?
answer
Effervescence is bubbling and fizzing when a gas is given off .
Calderglen High School

24. Calderglen High School
23. Give the SYMBOLS for the elements - lead, gold, sodium, potassium and iron?
answer
Lead – Pb
Gold – Au
Sodium – Na
Potassium – K
Iron - Fe
Calderglen High School

25. 24. What is the difference between COLOURLESS and CLEAR?
answer
Colourless means having no colour. Clear means you can see through something.
Calderglen High School

26. 25. SOLUBLE means …….. the substance dissolves in the solvent answer
Calderglen High School