Answers

2016-03-19T11:07:53+05:30
1)  no of molecules = 18/18 = 1 x 6.022x10^23 = 6.022 x 10^23
2) Its valency will be 3
3)Its atomic no = 5
valency = 3
element = boron 
4) 6.022x10^23
5)0.2 x 32 = 16
2 x 44 = 88

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