transition metals question

guys what is this ?? how are we supposed to know? the answer is C

now what i already know is that successive ionsiation energies show a gradual increase in ionisation energies until all the 4s and 3d electrons have been removed .. theres then a big jump as electrons start to be removed from the inner core electrons....... none of those show that ...\

pleasee help

Hi,

If you compare the values from the table , you can exclude anything but C. First of all, you need to remember that transition elements are located in d-block. It should allow you to cancel A and B , as in A , there is a jump between 1st and 2nd IE, thus it is more likely to be element in s-block, so no transition metal. The same applies to B, there is a jump between 2nd and 3rd IE, so more likely to be s-block as well. If you look at answer D, you can't really see any jumps between IE at all, also First IE seems to be really big, so the only answer that is left is C. And also C has a jump between 7 and 8 IE, thus possible electron configuration will be ...3s2 3p5 which is a transition element.

okay but first and sec are possible cos what is there is only 1 or 2 electrons in the 4s are thats it!!!

You will not see such a big jump there, because, if you remember the shell energy diagram, 4s is almost the same energy level as 3d.3d even has slightly higher energy than 4s.