JEE Advanced Model Paper 17 with solutions for online practice

Question : 39 of 60

Marks: +1, -0

Find out total number of metals cation(s) which form coloured metaborates:
Al3+ (aq) , Fe3+ (aq) , Pb2+ (aq) , Cd2+ (aq) , Mg2+ (aq) , Cr2+ (aq) , Ag+ (aq) , Zn2+ (aq) , Mn2+ (aq)