2.What is the percent composition by mass of the element oxygen in the compound H2SiO3 . (1) a)41,5% b) 51,5% c) 61,5% d)21,5% e)31,5%
3.Two of the reactions of element X are given below. What type of an element can X be? (1)
X +2HCl →XCl₂+ H₂ X + 2NaOH →Na₂XO₂+ H₂
a) Zn b) P c) Ar d) Ca e) Na

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