What element is represented by this electron ground state configuration :
[Kr] 4d10 4f14 5s2 5p6 5d10 5f14 6s2 6p6 6d2 7s2
Is this really Krypton?
No, [Kr] means all of the shells up to and including Kr are filled in so you have the 36 electrons for Kr PLUS all of the other electrons shown.
To determine the element represented by the given electron configuration, we need to look at the last (highest) energy level and count the number of electrons in it. In this case, the last energy level is the 7th principal energy level.
The electron configuration [Kr] 4d10 4f14 5s2 5p6 5d10 5f14 6s2 6p6 6d2 7s2 tells us that there are 2 electrons in the 7s sublevel, which means there are 2 valence electrons in the outermost energy level.
Since we have 2 valence electrons, this electron configuration represents the element in group 2 of the periodic table. And yes, the symbol for the element represented by this electron configuration is indeed Krypton (Kr).
So, to summarize, the element represented by the given electron configuration is Krypton (Kr).