BS132 Lecture 1

Describe Protons

1u mass, positive, 1.67×10^-27kg

Describe Electrons

Negligible mass, negative, 9.11×10^-31kg

Describe Neutrons

1u mass, no charge

How does the mass of electrons relate to the mass of protons?

1 e(-) = 1/2000 x p(+)

What is Mass Number?

Protons + Neutrons

What is Atomic Number?

Number of Protons or Electrons

What does a Lewis Diagram show?

Valence electrons only

What are Atomic Orbitals?

3D areas w/in which electrons may be

Types of s and p orbitals

s, Px, Py, Pz

What is the Aufbau Principle?

Electrons enter the lowest energy orbital that’s available

What does Degenerate mean?

Equal in energy

What is Pauli’s Exclusion Principle?

Orbitals accomodate a max of 2 electrons and they must have opposite spins (spin paired)

What is Hund’s Rule of Max Multiplicity?

Lowest energy configuration for a partially occupied set of degenerate orbitals has as many e(-)s as possible residing in different orbitals w/ their spins in same direction