Lecture 11 - Molecular Orbital Theory

These flashcards cover key concepts from the lecture on Molecular Orbital Theory, focusing on bond characteristics and electron behaviors in atomic and molecular orbitals.

What happens when two separate atoms come together in terms of electron sharing?

Electrons begin to be shared between the two nuclei.

What occurs when nuclei are too close together?

The nuclei repel each other.

What is the equilibrium bond distance for covalent bonds?

Approximately 1 Å.

What does the unit Angstrom (Å) represent in terms of distance?

1 Å is 10^-10 m (0.1 nm).

What is the Bohr radius?

The most probable distance between a proton and an electron in a hydrogen atom, which is 0.53 Å.

How many electrons can occupy each atomic orbital?

2 electrons.

What is the result of mixing two 1s orbitals in the same phase?

An orbital with lower energy is formed.

What happens when two 1s orbitals in opposite phases mix?

An orbital with a node (higher energy) is formed.

What are sigma (σ) orbitals?

Orbitals that look round like s orbitals and are associated with sigma bonds.

What distinguishes bonding and antibonding molecular orbitals?

Bonding orbitals have no node between the nuclei, while antibonding orbitals have a node.

In the He₂+ cation, how many electrons does the bonding orbital have?

2 electrons.

What happens to the energy of electrons in He₂+ compared to those in a single He atom?

Electrons in He₂+ have lower energy than those in 1 He atom and 1 He+ ion.

What is used to describe the electrons in molecular orbitals?

Four quantum numbers.

What is unique about the wavefunctions of Molecular Orbitals?

They are more complex, but quantum numbers still hold.