1. Edexcel Additional Chemistry (C2) Revision – Mrs. Moon

2. Mendeleev  Explain how Mendeleev arranged the elements in a periodic table  Predict the properties of missing elements  Classify elements as metals or non-metals

3. The structure of an atom

4. The structure of an atom (again!) Learn this! particlepositionchargemasssymbol protonnucleus+11p Neutronnucleus01n electronShell/orbital~0e

5. The Periodic table – you don’t need to remember them, just know what the numbers mean

6. What do the numbers mean? Atomic Number (number of protons) Element symbol Atomic mass The Atomic mass is always the biggest number Atomic mass = number of protons + number of neutrons

7. Columns down = groups And indicate how many electrons are in the outer shell Rows across are called = periods and indicate how many Electron shells the element has

8. Isotopes - H

9. H paper - Isotopes  An isotope has the same number of protons, but a different number of neutrons – so –  The atomic number will be the same, but the mass number is different

10. Electron (always negative)  Atoms have the same number of electrons as they do protons/Atomic number  Helium – Atomic number 2, proton number 2, electron number 2  Neon – atomic number 10, proton number 10, electron number 10  Simples!

11. Electron shells  Electrons are like soldiers on parade– they are arranged in a very specific order! 2, 8, 8

12. Period table and electron shells

13. Ions are atoms that have lost or gained electrons  Atoms like full outer shells and chemical reactions are atoms achieving this  One way is by becoming an ion

14. Ionic bonds  Ionic Bonds  when electrons have been given away or received, those atoms become either positive or negative  Positives and negatives attract  Forming an ionic bond

15. Ionic compounds Ionic compounds can keep growing and growing and become very big – like salt Ionic compounds are formed between metals and non-metals

16. Ionic bonds Cations Anions What are cations? Cations are atoms which loses electrons to obtain a noble gas structure. Hence, it has a positive charge. e.g A magnesium atom (An atom of a metal) loses two electrons to form a magnesium ion in its compound. What are anions? Anions are atoms which gains electrons to obtain a noble gas structure. Hence, it has a negative charge. e.g A chlorine atom (An atom of a non-metal) gains an electron to form a chloride ion in its compound.

17. Ionic compounds  Working out a formula

18. Formula of ionic compounds Ca looses 2 electrons So becomes +2 Cl gains 1 electron so becomes -1 (remember electrons are -1=negative To make a zero charge you will need 2 x Cl-1 to cancel out Ca+2 Try the last 3 yourself

19. Properties of ionic compounds  H paper To conduct electricity an ionic compound must:  Contain charged particles (be positive or negative)  Be free to move (in solution)

20. Ion tests

21. Some key words to know  Soluble – will dissolve into a liquid  Insoluble – will not dissolve in a liquid  A salt – and acid + an alkali  Precipitates – an insoluble solid appears at the end of a reaction  State symbols;  (s) = solid; (l) = liquid; (g) = gas;  (aq) = aqueous/in water

22. Covalent bonds – share electrons to gain a full outer shell

23. Properties of covalent substances

24. Covalent bonds

25. Properties of covalent structures  H paper  Most covalent compounds are tiny molecules and gases e.g. carbon dioxide  Diamond and graphite are unusual as they are covalent, but giant compounds  A why is graphite used as a lubricant (reduces friction – makes things slippy)

26. Properties of covalent substances

27. Miscible or immiscible

29. Metallic bonding

30. Alkali Metals

31. Halogens

32. Nobel Gases Structure Noble gases are in group 0. This means they have a full outer electron field, this makes them un-reactive. This also means they are monatomic - do not join with other elements that are the same, but are single and alone. As you move down the periods, the gases have an increasing boiling point and also density. Uses Probably the most famous noble gas is Helium, as it is used in balloons. This is because it 'floats' due to the fact it is less dense than air, so rises above it, and is completely safe since it is un-reactive. However, the densities increase as you go down the group.

33. Rates of reaction

36. Collision theory