How many of the following statements are correct ?
(i) Lanthanoids are silvery white metals and tarnish in air
(ii) Actinoids are silvery in appearance
(iii) The chemistry of the actinoids is much more complicated than the lanthanoids
(iv) Both $L{a}^{3+}$  and $L{u}^{3+}$  are yellow coloured in aqueous solutions
(v) Among actinoids, the elements in the first half of the series frequently exhibit higher oxidation states.
(vi) The magnetic properties of the actinoids are more complex than those of the lanthanoids