18. complete the noble gas notation for the following element: e. selenium

Explanation:

Step1: Determine the nearest noble gas before selenium

Selenium has an atomic number of 34. The nearest noble - gas with a lower atomic number is argon (Ar) which has an atomic number of 18.

Step2: Write the electron configuration after argon

The remaining electrons are (34 - 18=16). The electron - configuration after argon is (4s^{2}3d^{10}4p^{4}).

Answer:

([Ar]4s^{2}3d^{10}4p^{4})