Orgo Ch 1

Concepts and Vocab

How is an atom described by?

Atomic number, mass number, isotopes, amd atomic weight.

What are the rules for electron configuration?

Aufbau Principle, Pauli exclusion principle, and Hund’s rule.

What is the Aufbau principle?

Where the lowest energy orbital will fill first. 1s→2s→2p…

What is the Pauli Exclusion Principle?

Only 2 electrons can be in an orbital, and they have to be opposite spins,

What is Hund’s Rule?

If there is more than one orbital available in a shell, one electron will fill them until they are all half full.

Tetravalent

forming four bonds. i.g. carbon

Why are bonds stable?

When making bonds they release energy making them less chaos. When you break bonds, the absorb energy.

Molecules are…

Covalent bonds. never ionic bonds.

What does the number of bonsa depend on?

how many valence electrons are needed to form an octet.

What is valence bond theory?

once the electrons are shared and their orbitals from their atoms overlap with each other, the electrons are then attracted to both atoms nucleus, bonding the atoms together based off the attraction the electrons have to each.

Sigma bonds are…

formed by the head-on overlap of 2 atomic orbitals

Bond strength…

is the amount of energy needed to break a molecule, can be found by the energy released when making the molecule.

Atomic number

is the number of protons present in the nucleus

Mass number

total of the protons and neutrons in the nucleus

Isotopes

Atoms that have the same atomic number but different mass numbers because of neutrons.

Atomic Weight

The average weight of each common/naturally occurring isotopes.

Orbitals

the space an electron will occupy around the nucleus, each can contain 2 electrons

Ground State Electron Configuration

the orbital that are occupied by its electrons. Another way to identify atoms. i.g. Oxygen is 1s²2s²2p⁴

Octet Rule

The attempt to fill their valence shell. In the 2nd row, they have eight spaces to fill and need eight electrons to fill their shell. The atoms will either gain, lose, or share their electrons to reach the closest noble gas configuration.

Why is Carbon Special?

Carbon has four valence electrons and four spaces to fill. It is in the middle of row and ready to share in favor to get to a full octet.

Molecular Orbital Theory

chemical bonds as the combination of atomic orbitals to make molecular orbitals that can stretch

Pi bonds are…

the side-by-side overlap of atomic orbitals above and below the nucleus’ axis in p-orbitals