Question

what is the electron configuration for tc? select the correct answer below: kr4d^7 kr5s^25p^5 kr5s^24d^5 kr

Explanation:

Step1: Identify atomic number of Tc

Technetium (Tc) has an atomic number of 43. Krypton (Kr) has an atomic number of 36.

Step2: Determine electron - filling order

After the noble - gas core of Kr, electrons fill the 5s orbital first and then the 4d orbitals. The 5s orbital can hold 2 electrons and the 4d orbital can hold 10 electrons.

Step3: Write electron configuration

We start with the noble - gas core of Kr, then add the remaining electrons. After Kr, we have 43 - 36=7 electrons to place. The first 2 go in the 5s orbital and the remaining 5 go in the 4d orbital. So the electron configuration of Tc is $[Kr]5s^{2}4d^{5}$.

Answer:

$[Kr]5s^{2}4d^{5}$