Question 33 Answer and Explanation _ACT 2008 Form 61B Science Section

Passage VI

An atomic orbital can contain 0, 1, or 2 electrons. It is filled when it contains 2 electrons. An orbital's location and shape are determined by its energy level and sublevel. Table 1 lists the first 4 energy levels, their sublevels, and the number of orbitals in each sublevel.

Table 2 names each of the sublevels in the first 4 energy levels.

Table 3 shows the order in which the sublevels are filled with electrons. Each sublevel must be filled before an electron can be added to the next sublevel.

Tables 4 illustrates a notation used to indicate the number of electrons per sublevel.

33. If an atom in its ground state has 21 electrons, it will have more electrons in its:

A. 2s sublevel than in its 2p sublevel.

B. 2p sublevel than in its 3p sublevel.

C. 3s sublevel than in its 4s sublevel.

D. 4s sublevel than in its 3d sublevel.

Answer and Explanation

Your Answer is

Correct Answer is D

Explanation

According to table 4, when there are 21 electrons, it should be 1s22s22p63s23p64s23d1, so the 4s sublevel contains more electrons than the 3d sublevel