2. First Something Familiar What do the following items have in common?

4. What common traits did you notice?

5. Now, Something Not Familiar What do the following items have in common? Use your note-taking template to list some common traits for the examples you see

6. 32 grams of Sulfur 12 grams of carbon Examples of the Mole 201 grams of Mercury 55.8 grams of Iron

7. Chemists use the idea of the mole when comparing the number of particles of different substances.

8. How many atoms are there in 12 g of carbon (one mole)?

9. This is the number of atoms in 12 g of carbon or one mole of particles.

10. It is called the Avogadro constant.

11. If you started counting 220 million carbon atoms per second 85 million years ago, you might just have finished counting a mole of them about now.

12. 12 g of carbon contains 1 mole of carbon atoms, or 1 mol for short.

13. How many moles of sulphur atoms are there in 32 g of sulphur?

14. Notice that the mass of one mole is the equal to the relative atomic mass in grams.

15. So, how many moles of iron atoms are there in 56 g of iron?

16. If you know the A r or M r of a substance, you can easily work out the mass of one mole of that substance.

17. This is the relationship between moles, grams and molar mass.

18. This ‘magic triangle’ might help you in calculations.

19. What is the amount in moles of carbon atoms in 6 g of carbon?

20. The mass is grams in 6.

21. The A r of carbon is 12 so its molar mass is 12 g mol -1.

22. There are 0.5 mol of carbon atoms in 6 g of carbon.

23. This is the relationship between moles, grams and molar mass.

24. This ‘magic triangle’ might help you in calculations.

25. What is the mass of 2 moles of calcium carbonate, CaCO 3 ?

26. The M r of calcium carbonate is 100 so its molar mass is 100 g mol -1.

27. The amount in moles is 2.

28. 2 moles of calcium carbonate, CaCO 3, have a mass of 200 g.