1.What always happens in a chemical reaction ? A new substance is always formed in a chemical reaction answer
2.What changes might indicate that a chemical reaction has taken place? Energy change Permanent colour change Gas produced (effervescence) Solid formed in a liquid (precipitation) answer
3.An element is ……… An element is the simplest type of substance. It is made up of only 1 type of atom. answer
4.What is a GROUP in the Periodic Table? A column of elements answer
5.What is a PERIOD in the periodic table? A row of elements answer
6.Why are certain elements in the same group? Because they have similar chemical properties answer
7.Give some metallic properties? Conduct electricity and heat Malleable (bend into shape) Ductile (draw into wires) Most of them are strong answer
8.What are compounds? Substances made of two or more different types of atom joined together. answer
9.What is the difference between a compound and a mixture? The atoms of a compound are joined together. The substances in a mixture are NOT joined and can be easily separated. answer
10.What is a molecule ? Two or more non metal atoms joined together Can be element e.g. O 2, H 2 OR compound e.g. H 2 O, CO answer
11.What does -ide at the end of the name of a compound indicate? IDE means that the compound is made up of the TWO elements (the actual elements are obvious from the compound’s name). answer
12.What is ELECTROLYSIS? Using ELECTRICITY to break up a compund. answer
13. Write a word equation for: Methane burns in oxygen to produce carbon dioxide. Water is also produced. Methane + Oxygen Carbon + Water Dioxide answer
Chemical ReactionPhysical Change 14. Sort these into chemical reaction and physical change. Hair growing Ice melting Match burning Boiling Water Baking cake Firework exploding answer Hair growing, Ice melting, Match burning, Baking cake, Firework exploding, Boiling water
15.Describe how the concentration of reactants affects the speed of a reaction? As reactant concentration increases the speed of reaction increases.
16.What is meant by a property of a chemical? A property of a chemical is what it is like or what it can do chemically answer
17. Name FOUR factors which affect the speed (or rate) of a chemical reaction? Particle Size (Surface Area) Temperature Concentration Use of Catalyst
18.When can a catalyst NOT speed up a reaction? SOME reactions DO NOT have a catalyst. SOME reactions DO NOT have a catalyst.
19.Where in the Periodic Table would you find the METALS and the NON-METALS? Metals are found to the Left Hand Side of the zigzag line; Non-metals to the Right Hand Side of the zig-zag line answer
20.What are ATOMS? Atoms are very small, particles which make up every element. They are too small to see. answer
21.What is a PRECIPITATE? A precipitate is a solid which is formed when two solutions react together answer
22.What is EFFERVESCENCE? Effervescence is bubbling and fizzing when a gas is given off. answer
23. Use the Periodic Table in your planner. Give the SYMBOLS for the elements : lead, gold, sodium, potassium and iron? Lead – Pb Gold – Au Sodium – Na Potassium – K Iron - Fe answer
24.Describe how particle size affects the speed of reaction? As particle size decreases the As particle size decreases the speed of reaction increases speed of reaction increases
25. Describe how temperature affects the speed of reaction? As temperature increases the speed of reaction increases As temperature increases the speed of reaction increases
26.What are ENZYMES? Catalysts from living things (Biological catalysts) Catalysts from living things (Biological catalysts)
27.What is a catalyst? A substance which can speed up a reaction, but is not used up in the reaction and can be recovered chemically unchanged
28.Why does decreasing the particle size of reactants increase the speed of reaction? Smaller particles give a bigger surface area. This results in more collisions between reactants and therefore faster reactions
29.What must be controlled when carrying out experiments to compare speeds of reaction? All variables other than the one being tested must be kept the same in all experiments All variables other than the one being tested must be kept the same in all experiments
30.What is a VARIABLE? Any factor in an experiment which can be changed or varied. e.g. concentration or temperature Any factor in an experiment which can be changed or varied. e.g. concentration or temperature of the solution used of the solution used
31.Rates Experiments Which two of the following experiments could be used to find the effect of changing the particle size?
2M hydrochloric acid at 25 0 C 2g of large chalk lump 2g of small chalk lumps A 2M hydrochloric acid at 15 0 C 2g of small chalk lumps B C 1M hydrochloric acid at 25 0 C 2g of small chalk lumps D
32.Rates Experiments Which two of the following experiments could be used to find the effect of changing the concentration of the acid?
2M hydrochloric acid at 25 0 C 2g of small chalk lumps A 2M hydrochloric acid at 15 0 C 2g of small chalk lumps B 2M hydrochloric acid at 25 0 C 2g of large chalk lump C 1M hydrochloric acid at 25 0 C 2g of small chalk lumps D
33.Rates Experiments Which two of the following experiments could be used to find the effect of changing the temperature of the acid?
2M hydrochloric acid at 25 0 C 2g of small chalk lumps A 2M hydrochloric acid at 15 0 C 2g of small chalk lumps B 2M hydrochloric acid at 25 0 C 2g of large chalk lump C 1M hydrochloric acid at 25 0 C 2g of small chalk lumps D