Question

Designate the orbital that fits each of the following descriptions: (a) a spherical orbital in the fifth energy level (b) a dumbbell-shaped orbital in the fourth energy level

Short answer

(a) 5s orbital; (b) 4p orbitals.

Step-by-step solution

Identify the Orbital Shape for Part (a)

A spherical orbital corresponds to the 's' orbital type. In any energy level, the 's' orbital is always spherical.

Determine the Energy Level for Part (a)

The question specifies the fifth energy level. Thus, for the fifth energy level, the spherical orbital is the 5s orbital.

Identify the Orbital Shape for Part (b)

A dumbbell-shaped orbital refers to the 'p' orbital type. In each energy level starting from the second, there are three 'p' orbitals.

Determine the Energy Level for Part (b)

The question specifies the fourth energy level. Thus, for the fourth energy level, the dumbbell-shaped orbitals are the 4p orbitals.

Key concepts

Orbital Shapes

Electrons in atoms are found in regions called orbitals, and these orbitals come in different shapes. The shape of an orbital determines where there's a high probability of finding an electron. In general:

• Spherical orbitals: These correspond to 's' orbitals. Every energy level (or shell) contains one 's' orbital, and they are perfectly spherical in shape. This means the electron can be found at any position within this sphere with equal probability.
• Dumbbell-shaped orbitals: These correspond to 'p' orbitals. The 'p' orbitals have a unique lobed shape that looks like a dumbbell, with two lobes on either side of a central node where there's zero electron probability. Starting from the second energy level, each level has three 'p' orbitals, each oriented differently in space (often called px, py, and pz).

Understanding these shapes is crucial as it directly affects the chemical bonding and properties of molecules formed.

Energy Levels

Atoms contain several energy levels or shells where electrons can reside. Each energy level is associated with a specific amount of energy. Understanding these levels involves recognizing how they're organized:

• The first energy level is closest to the nucleus and has the least energy, containing only an 's' orbital.
• As you move to higher energy levels (further from the nucleus), more orbitals become available, such as 'p', 'd', and 'f'.
• Each increase in energy level presents a new set of orbitals, contributing to the complex structures that exist in larger atoms.

For example, by the fourth energy level, not only are 's' and 'p' orbitals available, but 'd' orbitals are as well. Fifth energy level introduces 'f' orbitals even though the 5s ionic configuration is essential for determining this level's characteristics. Understanding the energy required to reach each level can help determine how elements bond and react.

s and p Orbitals

The 's' and 'p' orbitals are fundamental to comprehending atomic structure and chemical reactions:

• 's' Orbitals: Always spherical and present in every energy level. For instance, in the fifth energy level, this is referred to as a 5s orbital. It's the simplest orbital and typically represents where electrons first fill when moving to a new shell.
• 'p' Orbitals: These dumbbell-shaped orbitals become available starting from the second energy level. Each has three forms (along the x, y, or z axis), namely px, py, and pz. By the fourth energy level, you have the 4p orbitals, which are key in forming molecules as they tend to hold valence electrons that bond with other atoms.

Being aware of how 's' and 'p' orbitals function is pivotal for predicting electronic configurations and understanding molecular geometry in chemistry.