1.
How many electrons can the first energy level hold?
Correct Answer
A. 2
Explanation
The first energy level, also known as the K shell, can hold a maximum of 2 electrons. This is because the first energy level consists of only one subshell, which is the s subshell. The s subshell can accommodate a maximum of 2 electrons. Therefore, the correct answer is 2.
2.
What does the German word "Aufbau" mean?
Correct Answer
B. Building-up
Explanation
The German word "Aufbau" translates to "building-up" in English. This word refers to the process of constructing or assembling something, whether it be physical structures or abstract concepts. It implies a progression or growth towards a desired goal or outcome.
3.
Who formulated the Aufbau principle?
Correct Answer
C. Niels Bohr and Wolfgang Pauli
Explanation
The Aufbau principle, also known as the building-up principle, was formulated by Niels Bohr and Wolfgang Pauli. This principle states that electrons fill atomic orbitals of lower energy levels before filling higher energy levels. It provides a systematic way to understand the electron configuration of atoms and the order in which the orbitals are filled. Bohr and Pauli's work on the Aufbau principle contributed significantly to our understanding of atomic structure and the behavior of electrons in atoms.
4.
When was the Aufbau principle formulated?
Correct Answer
D. 1920
Explanation
The Aufbau Principle was formulated in the early 20th century. The term "Aufbau" comes from the German word meaning "building up" or "construction." The principle itself was developed primarily by Niels Bohr and Wolfgang Pauli in the 1920s, based on the work of earlier scientists like Gilbert N. Lewis and Irving Langmuir. Bohr introduced the concept of electron configurations in atoms, and Pauli further refined this with the Pauli Exclusion Principle. Together, these ideas laid the groundwork for the Aufbau Principle as we know it today.
5.
What is always the lowest energy sublevel for any atom?
Correct Answer
A. 1s
Explanation
The 1s sublevel is always the lowest energy sublevel for any atom. This is because the sublevels are organized in increasing energy levels, with the 1s sublevel being closest to the nucleus. As electrons occupy the lowest energy levels first, the 1s sublevel is filled before any other sublevel.
6.
Which of the following orbitals is not possible?
Correct Answer
B. 3f
Explanation
The possible orbitals are labeled as s, p, d, and f. The letter indicates the shape of the orbital, while the number indicates the energy level. The f orbitals are higher in energy and are found in the fourth and higher energy levels. Therefore, the 3f orbital is not possible as it would be found in the third energy level, which does not have f orbitals.
7.
What sublevel immediately follows the 2s sublevel according to the Aufbau principle?
Correct Answer
C. 2p
Explanation
According to the Aufbau principle, electrons fill the lowest energy levels first. The 2s sublevel is filled before the 2p sublevel. Therefore, the sublevel that immediately follows the 2s sublevel is the 2p sublevel.
8.
What sublevel immediately follows the 4s sublevel according to the Aufbau principle?
Correct Answer
D. 3d
Explanation
According to the Aufbau principle, electrons fill the orbitals in order of increasing energy. The 4s sublevel is filled before the 3d sublevel because the 4s sublevel has a lower energy. Therefore, the sublevel that immediately follows the 4s sublevel is the 3d sublevel.
9.
The highest energy electron of rubidium is in what principle quantum level?
Correct Answer
A. 5
Explanation
The principle quantum level refers to the main energy level or shell where an electron is located in an atom. In the case of rubidium, the highest energy electron is in the fifth principle quantum level. This means that the electron occupies the fifth energy level or shell, which is the outermost shell for rubidium.
10.
Which of the following elements is the symbol of element with the electron configuration described by the Aufbau diagram on the picture?
Correct Answer
B. P
Explanation
The Aufbau diagram in the picture represents the electron configuration of an element. The element with this electron configuration can be determined by looking at the position of the arrows in the diagram. In this case, the arrow is pointing to the third energy level, which corresponds to the third period of the periodic table. The element in the third period that matches this electron configuration is phosphorus (P).