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 3. What does this mean? toxic 4. What element does this represent? sodium Na 5. Which group is it in? 1 3 6. Which period is it in? 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. 9. How did they know that there was an undiscovered element in the sun? I’ve never seen that yellow line before when I’ve There must be been looking at an element on spectra. the sun we haven’t There were discovered lines that yet. Let’s call it helium after hadn’t been the Greek seen name for the before in sun. other spectra. 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. 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 14. Do they become more or Na less reactive as you go down the group? more K 15. Name the two Rb products: Cs 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. H2 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 H2O, NaCl, H2, Cl2, NaOH 28. Give any trends. Name Hardness Density Melting point g/cm3 oC Lithium Fairly hard 0.53 180 to cut Sodium Easy to cut 0.97 98 Potassium Very easy to 0.86 64 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? • 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. 30. What happens to a chlorine atom when it reacts? Cl 2.8.7 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 2.8.1 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 Mg2+ (Group 2) • Aluminium Al3+ (Group 3) • Fluorine F- (Group 7) • Oxygen O2- (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.
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