Answers

2016-03-16T20:14:38+05:30
The shiny brown coloured element 'X' is copper and the black coloured compound formed is Copper oxide. The reaction involved is 
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2016-03-16T20:29:50+05:30
The brown coloured element is copper. by the experiment of oxidation we will observe black color copper oxide.
prediction:
cu+02=>2Cuo
CuO+H2=>Cu+H2O
this is in the presence of heat
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