7B, 7C, Math and science

 Gold alloy

https://www.youtube.com/watch?v=8rQ0SkItHH0

Grade Seven Science: Solid-Solid Mixtures (alloys)

Gold alloy (first video, composition of 24K, 22K, 18K gold, and how it is

calculated)

https://www.youtube.com/watch?v=8rQ0SkItHH0

1. Purity of gold is calculated in the unit ___________ or __________ and not carrot

2. Maximum purity of gold is _______K or 100% pure gold

3. Pure gold is very ________ and can _________ easily

4. We need to add other metals to make it ___________

5. 18K gold is _____% pure. Show your calculations:

6. 12K gold is _____% pure. Show your calculations:

7. 20K gold is _____% pure. Show your calculations:

8. Alloying is mixing gold with other ____________

9. Chemical symbol for gold is __________;

10. Chemical symbol for silver is __________

11. Chemical symbol for copper is __________

12. When we combine ________ and _______, we get white gold

13. When we combine ________ and _______, we get reddish rose gold

 

This video shows you how gold alloy is made.  Cool

https://www.youtube.com/watch?v=vd93NeJcopY

14. To begin, the woman uses 1oz of _________ pure fine gold, 1 Pennyweight ______

grains of silver and __________ grains of copper

15. 0.9999 gold = 99.99% pure gold

16. She uses the hard compressed __________ block to press the gold nuggets

17. Always __________ while heating

18. Tips 2: try to get the gold nuggets as _________ and ________ as possible

19. She tries to keep the ____________ steady. When the melted gold forms a _______ it is

ready for mixing and alloying

20. How to check for purity after melting? Looking for __________ finish and __________

on the gold ball

21. The alloy is this video is a mixture of gold, ________ and _________.

22. This forms a ____K gold alloy

23. First, she adds _________ to the melted gold. Follows by adding ___________

24. The colour of the 22K gold alloy is _________ than pure gold

25. After turning off the torch, let the alloy cools to a _________, then put it in ________

and we hear a hissing ____________

26. We must let the alloy sits in the water bowl for a while for it to cool off completely

Golden mouse