Signs of Chemical Reactions N3/4 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

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

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

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

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

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

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

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

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

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

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

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

(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

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

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

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

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

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

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

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

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

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

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

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

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

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