Presentation on theme: "1. What does this symbol mean? 2. Sodium has this hazard symbol - what precautions should you take when using it? corrosive Goggles, pick up with tweezers,"— Presentation transcript:
1. What does this symbol mean? 2. Sodium has this hazard symbol - what precautions should you take when using it? corrosive Goggles, pick up with tweezers, use a safety screen
3. What does this mean? toxic
4. What element does this represent? Na 5. Which group is it in? 6. Which period is it in? sodium 1 3
7. Which of these is the flame colour for sodium chloride? The yellow one
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.
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. 9. How did they know that there was an undiscovered element in the sun? There were lines that hadn’t been seen before in other spectra.
10. What is the name of the group which this element belong to? Cl 11. What does Cl 2 tell you? 2 atoms in a chlorine molecule. 12. Why am I added to water at the swimming pool? To kill bacteria. The Halogens (Group 7)
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
16. Inside an atom there are neutrons. What else are there? Protons and electrons
17. What word do we use to describe a charged particle like Na + ? ions
18. Element or compound? Compound because the atoms aren’t all the same.
19. Atom, molecule or ion? It is a molecule – a group of atoms joined together. H2H2
20. Atom, molecule or ion? Ion because it has a charge. Cl -
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.
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.
26. Why does melted salt or salt solution conduct electricity? The ions can move around and carry current.
27. What’s the formula? Water Sodium chloride Hydrogen Chlorine Sodium hydroxide H 2 O, NaCl, H 2, Cl 2, NaOH
28. Give any trends. NameHardnessDensity g/cm 3 Melting point o C LithiumFairly hard to cut SodiumEasy to cut PotassiumVery easy to cut As you go down the group, the elements get softer, there is no pattern in density, the melting point decreases.
29. What do they mean? H 2 O (l) Na (s) Cl 2 (g) NaCl (s) NaCl (aq) Water is a liquid, sodium is a solid, chlorine is a gas, sodium chloride solid and sodium chloride solution.
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 -
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 +
32. Give the ion for: Sodium Na + (Group1) Magnesium Mg 2+ (Group 2) Aluminium Al 3+ (Group 3) Fluorine F - (Group 7) Oxygen O 2- (Group 6)
33. Which are salts? Sodium Chlorine Sodium chloride Potassium bromide Magnesium iodine Salts are made when you react a metal with a non-metal.