Question

How many electrons are on the outermost energy level of selenium (Se), with an atomic number of 34, and what energy level is it located on?

A) 2 electrons, energy level 3
B) 4 electrons, energy level 4
C) 6 electrons, energy level 3
D) 8 electrons, energy level 4

Answer 1

The outermost energy level of selenium has six electrons and it is located on the fourth energy level, with the valence electron configuration being 4s²4p4. Therefore, the correct option is D.

Step-by-step explanation:

The outermost energy level of selenium (Se), with an atomic number of 34, is the fourth energy level. The valence electron configuration for selenium is 4s²4p4. This means that there are a total of six electrons in the outermost shell (n = 4), which is located on the fourth energy level. The correct answer is thus option B) 6 electrons, energy level 4. It's important to remember that within an energy level, electrons reside in sublevels such as s, p, d, and f. For selenium, which is in the 4th period of the periodic table, the highest occupied energy level is 4, and the electrons are distributed as 4s² for the s sublevel and an additional four electrons in the 4p sublevel, leading to a 4s²4p4 configuration.