The general electronic configuration of the transition elements is
(n-1)d10, (n+1)s2
(n- 1)d1-10, (n + 1)s1-2
(n- 1)d1-10, np6,ns2
(n- 1)d1-10, ns1-2
Select the coloured compound amongst the following .
(At. no. Ti= 22, Cr= 24, Cu= 29, Zn= 30)
TiCl4
CrCl3
ZnCl3
CuCl
The only radioactive element among the lanthanoids is
gadolinium
holmium
promethium
neodymium
C.
promethium
Among the lanthanoids, promethium is the only radioactive element.