According to the Aufbau principle, which orbital is filled immediately before each of the following? (a) 3p (b) 4p (c) 4f (d) 5d

Verified step by step guidance

Step 1: Understand the Aufbau principle, which states that electrons fill orbitals starting from the lowest energy level to the highest. This is often represented by the order of filling: 1s, 2s, 2p, 3s, 3p, 4s, 3d, 4p, 5s, 4d, 5p, 6s, 4f, 5d, 6p, 7s, 5f, 6d, 7p.

Step 2: For part (a), identify the orbital filled immediately before 3p. According to the order, 3s is filled before 3p.

Step 3: For part (b), identify the orbital filled immediately before 4p. According to the order, 3d is filled before 4p.

Step 4: For part (c), identify the orbital filled immediately before 4f. According to the order, 6s is filled before 4f.

Step 5: For part (d), identify the orbital filled immediately before 5d. According to the order, 4f is filled before 5d.

Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Aufbau Principle

The Aufbau principle states that electrons occupy the lowest energy orbitals first before moving to higher energy levels. This principle guides the order in which atomic orbitals are filled, ensuring that the most stable electron configuration is achieved. Understanding this principle is crucial for predicting the electron configuration of elements in the periodic table.

Orbital Energy Levels

Orbital energy levels refer to the different energy states that electrons can occupy within an atom. These levels are organized in a specific order based on their energy, with s, p, d, and f orbitals having increasing energy levels. Familiarity with these energy levels helps in determining which orbitals are filled in accordance with the Aufbau principle.

Electron Configuration

Electron configuration describes the distribution of electrons in an atom's orbitals. It is represented using a notation that indicates the energy levels and types of orbitals occupied by electrons. Knowing how to write and interpret electron configurations is essential for understanding chemical properties and reactivity of elements.