Question

How many electrons are needed to fill the first energy level?____(1) The second energy level? ____(2) Third energy level (if it is not the outermost level)? ____(3)

a. 2; 8; 18
b. 2; 8; 8
c. 2; 6; 10
d. 2; 10; 18

Answer 1

The first energy level requires 2 electrons, the second energy level can hold up to 8 electrons, and the third energy level also holds 8 electrons if it's not the outermost, but can hold up to 18 when it includes the 3d sublevel. Therefore, the correct answers are 2 for the first level, 8 for the second, and 18 for the third.

Step-by-step explanation:

The number of electrons needed to fill the first energy level is 2, as this level consists of a single s orbital, which can accommodate only two electrons. For the second energy level, which consists of one s orbital and three p orbitals, a total of 8 electrons are required to fill it up. When the third energy level is not the outermost level, it can hold a total of 18 electrons because it has one s orbital, three p orbitals, and five d orbitals. But if we are considering the filling of orbitals up to the 3p sublevel, only 8 electrons are required, similar to the second energy level. With this understanding, the correct answer to the question is (a) 2; 8; 18.