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1. What does this symbol mean?

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Presentation on theme: "1. What does this symbol mean?"— Presentation transcript:

1 1. What does this symbol mean?
corrosive 2. Sodium has this hazard symbol - what precautions should you take when using it? Goggles, pick up with tweezers, use a safety screen

2 3. What does this mean? toxic

3 4. What element does this represent?
sodium Na 5. Which group is it in? 1 6. Which period is it in? 3

4 7. Which of these is the flame colour for sodium chloride?
The yellow one

5 8. What can you say about the spectrum for each element?
Each element has a different spectrum, it can be used to identify the element.

6 9. How did they know that there was an undiscovered element in the sun?
There must be an element on the sun we haven’t discovered yet. Let’s call it helium after the Greek name for the sun. I’ve never seen that yellow line before when I’ve been looking at spectra. There were lines that hadn’t been seen before in other spectra.

7 10. What is the name of the group which this element belong to?
The Halogens (Group 7) Cl 11. What does Cl2 tell you? 2 atoms in a chlorine molecule. 12. Why am I added to water at the swimming pool? To kill bacteria.

8 13. What do these alkali metals have in common
13. What do these alkali metals have in common? Soft, silvery, one electron in outer shell, react with water to make hydrogen and an alkaline solution, all end in ium, metals …. Li Na K Rb Cs 14. Do they become more or less reactive as you go down the group? more 15. Name the two products: Sodium + water  sodium hydroxide + hydrogen

9 16. Inside an atom there are neutrons. What else are there?
Protons and electrons

10 17. What word do we use to describe a charged particle like Na+? ions

11 18. Element or compound? Compound because the atoms aren’t all the same.

12 19. Atom, molecule or ion? It is a molecule – a group of atoms joined together.

13 20. Atom, molecule or ion? Ion because it has a charge.

14 21. If my electron configuration is 2,8,1; what group am I in
21. If my electron configuration is 2,8,1; what group am I in? 1 because there is one electron in the outer shell. 22. What period am I in? Period 3 because 3 shells are used.

15 23. Why does sodium chloride have a high melting point
23. Why does sodium chloride have a high melting point? There is a strong attraction between the + and – ions and a lot of energy is needed to pull them apart. 24. Why are salt crystals cubic? The ions are arranged in a regular way – in a lattice. 25. Why don’t salt crystals conduct electricity? The ions are fixed in position and can’t move around.

16 26. Why does melted salt or salt solution conduct electricity?
The ions can move around and carry current.

17 27. What’s the formula? Water Sodium chloride Hydrogen Chlorine
Sodium hydroxide H2O, NaCl, H2, Cl2, NaOH

18 28. Give any trends. Name Hardness Density g/cm3 Melting point oC
Lithium Fairly hard to cut 0.53 180 Sodium Easy to cut 0.97 98 Potassium Very easy to cut 0.86 64 As you go down the group, the elements get softer, there is no pattern in density, the melting point decreases.

19 29. What do they mean? H2O (l) Na (s) Cl2 (g) NaCl (s) NaCl (aq)
Water is a liquid, sodium is a solid, chlorine is a gas, sodium chloride solid and sodium chloride solution.

20 30. What happens to a chlorine atom when it reacts?
Cl The atom will gain an electron to get a full outer shell. It will become Cl-

21 31. What happens to a sodium atom when it reacts?
Na The atom will lose an electron to get a full outer shell. It will become Na+

22 32. Give the ion for: Sodium Na+ (Group1) Magnesium Mg2+ (Group 2)
Aluminium Al3+ (Group 3) Fluorine F- (Group 7) Oxygen O2- (Group 6)

23 33. Which are salts? Sodium Chlorine Sodium chloride Potassium bromide
Magnesium iodine Salts are made when you react a metal with a non-metal.

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