Electron Structure Flashcards

Questions and Answers

Why is bromine classified as a p-block element?

The outermost electrons are in the p-subshells.

What is the electron configuration of Cr and the Cr3+ ion?

Cr: 1s2, 2s2, 2p6, 3s2, 3p6, 4s1, 3d5; Cr3+: 1s2, 2s2, 2p6, 3s2, 3p6, 3d3.

What is an orbital? Describe it.

An orbital is a region that can hold up to two electrons, with opposite spins.

Describe the shapes of s and p orbitals.

s orbitals are spherical and can hold two electrons; p orbitals are in the shape of a dumb-bell and can hold two electrons in each orbital. Signup and view all the answers

State the number of orbitals making up s-, p-, and d-subshells.

s subshell: 1 orbital; p subshell: 3 orbitals; d subshell: 5 orbitals. Signup and view all the answers

State the number of electrons that occupy s-, p-, and d-subshells.

s subshell: 2 electrons; p subshell: 6 electrons; d subshell: 10 electrons; f subshell: 14 electrons. Signup and view all the answers

State Aufbau's Principle.

Fill the orbitals in order of energy levels. Signup and view all the answers

State Hund's Rule.

For orbitals with the same energy, occupation singly before pairing. Signup and view all the answers

Describe the relative energies of s-, p-, and d-orbitals for shells 1, 2, 3 and the 4s and 4p orbitals.

1s < 2s < 2p < 3s < 3p < 4s < 3d < 4p. Signup and view all the answers

Classify the elements into s, p, and d blocks.

s-block: first two groups, plus hydrogen and helium; p-block: group 3 to group 0 minus helium; d-block: transition metals. Signup and view all the answers

Study Notes

Electron Structure and Orbital Concepts

Bromine is a p-block element because its outermost electrons are located in p-subshells.
The electron configuration of Chromium (Cr) is 1s² 2s² 2p⁶ 3s² 3p⁶ 4s¹ 3d⁵, while that of its Cr³⁺ ion is 1s² 2s² 2p⁶ 3s² 3p⁶ 3d³.

Orbitals and Their Shapes

An orbital can accommodate a maximum of two electrons that have opposite spins.
s orbitals have a spherical shape, holding a total of two electrons; p orbitals have a dumbbell shape, with each orbital capable of holding two electrons.

Subshells and Electron Capacity

The s subshell contains one orbital (2 electrons), the p subshell has three orbitals (6 electrons), and the d subshell consists of five orbitals (10 electrons).
An f subshell has seven orbitals and can hold up to 14 electrons.

Principles of Electron Configuration

Aufbau's Principle states that electrons occupy orbitals in order of increasing energy levels.
According to Hund's Rule, electrons will fill orbitals of the same energy singly before pairing in order to minimize repulsion.

Relative Energy of Orbitals

The 1s subshell has the lowest energy level, followed by the 2s and 2p subshells.
Within the third shell, the 3s subshell is filled first, followed by 3p.
The 4s subshell is filled before the 3d subshell, subsequent filling order is 4p, then 4d, and finally 4f.

Classification of Elements

The s-block elements include the first two groups of the periodic table, along with hydrogen and helium.
The p block comprises groups 3 to 0, excluding helium.
The d block consists of transition metals.

Description

Test your knowledge of electron structure with these flashcards. Covering various concepts such as p-block elements, electron configurations, and orbitals, this quiz is perfect for students looking to enhance their understanding of chemistry. Perfect for exam preparation and revision.