A, B and C are three elements which undergo chemical reactions according to following equations.
`A_(2)O_(3) + 2B to B_(2)O_(3) + 2A`
`3CSO_(4) + 2B to B_(2)(SO_(4))_(3) + 3C`
`3CO + 2A to A_(2)O_(3) + 3C`
Answer the following questions :
(a) Which element is the most reactive ? (b) Which element is the least reactive ?

a) A, B and C are 3 elements which undergo chemical reaction according to following equations a) A_2O_3 +2B to B_2O_3 + 2A b) 3CSO_4 + 2B to B_2(SO_4)_3 + 3C c) 3CO + 2A to A_2 SO_3 + 3C Answer the following: i) Which element is most reactive? ii) Which element is least reactive? b) Why is ZnO called amphoteric oxide? Name another amphoteric oxide.

P,Q and R are 3 elements which undergo chemical reactions according to the following equations: a. P_(2)O_(3)+2QtoQ_(2)O_(3)+2P (ii) 3RSO_(4)+2Qto(SO_(4))(3)+3B c. 3RO+2PtoP_(2)O_(3)+3R Answer the following questions: (i) Which element is least reactive? (ii) Which element is least reactive? (iii) State the type of reaction listed above.