一些化学问题（英文版）
1.Ionic compounds have very high melting points.Explain at least two forces that cause this physical characteristic.
2.List bonds in order of bond strength
a.Hydrogen bond between H2O
b.Covalent bond between H and O in water
c.Ionic bond between NA+ and Cl-
d.Covalent bond between the two hydrogen atoms in hydrogen gas H2
3.How many calories would it take to boil 100g of water that started at 25 oC?if one calorie equals 4.184 Joules,how many Joules would it take to boil the same 100g of water starting at 25 oC?
最好用英文回答哈,