1) (i) you are right.
- (ii) Mg > Zr > Zn > Ni
- (iii) should be (-)
2 (a) it's right.
(b) check you note. it should be something - radiation going in the tube. ionise the argon ion in the air, etc.
3 (a) it is an ester because it has the COOC group, but glycolic acid doesnt, so it's not an...