1.) why were coins originally made from precious metals such as gold or silver rather than cheaper metals such as copper? 2.) what is the major difference in metal composition of canadian coins compared with american ones?

In the old time the people were not aware of unrestorable resources like minerals.In mid-centuries there was kingdoms rule.The kings were proud of their wealth so they use Gold and silver coins.As they are so precious kings could show more prestige .

#2

American coins contain 75% copper and 25% nickel.On the other hand Canadian coins were of pure nickel.

Ch4 is nonpolar and insoluble in water. since all of the hydrogen atoms are evenly spread around the carbon atom even through the c h bond is polar all the poles cancel each other out.