Chemistry Lecture: Matter, Atomic Structure, and Quantum Mechanics

How is Chemistry defined in the notes?

The branch of science that deals with the study of matter and its changes.

What are the three main branches of Chemistry mentioned?

1. Organic Chemistry (deals with carbons and hydrogen derivatives); 2. Inorganic Chemistry (deals with study of elements except carbon and hydrogen); 3. Physical Chemistry (study of energy, physical properties, and measurement).

What is the physical definition of Matter?

Anything that has mass and occupies space.

What are the three types of Van der Waal forces listed?

i) dipole-dipole forces, ii) dipole induced dipole, and iii) London dispersion force.

According to Dalton’s Atomic Theory, what are the fundamental building blocks of matter?

Matter consists of very small particles called atoms.

What was the key outcome of Dalton’s theory regarding the creation of matter?

Atoms can neither be created nor destroyed.

What are some modern drawbacks to Dalton's Atomic Theory identified in the notes?

Atoms can be destroyed; atoms are divisible into sub-atomic particles (electron, proton, neutron); and in isotopes, properties of the same element are different.

What are the absolute charge and mass (in kg) of an electron?

Absolute charge: $-1.6 \times 10^{-19}\,C$; Relative mass: $9.1 \times 10^{-31}\,kg$.

What are the absolute charge and mass (in kg) of a proton?

Absolute charge: $+1.6 \times 10^{-19}\,C$; Mass: $1.672 \times 10^{-27}\,kg$.

Define Isotopes.

Atoms of the same element having the same Atomic Number ($Z$) but different Mass Number ($A$).

Define Isobars.

Atoms of different elements having the same Mass Number ($A$) but different Atomic Number ($Z$).

What are Isotones (Isotonic)?

Atoms of different elements having the same number of neutrons.

What are Isodiaphers (spelled 'Isodiaphres' in text)?

Atoms of different elements having the same difference in the number of neutrons and protons ($n - p$).

Define Isosters.

Molecules having the same number of atoms and same number of electrons (e.g., $CO_2$ and $N_2O$).

What are Isoelectronic species?

The species which contain the same number of electrons.

What is the difference between an Orbit and an Orbital?

An orbit is a circular path around the nucleus where electrons revolve; an orbital is the region of space around the nucleus where the probability of finding an electron is maximum.

What information does the Principal Quantum Number ($n$) provide?

It gives information about the size and energy of the orbital as well as the name of the shell ($K$, $L$, $M$, etc.).

What is the formula for the maximum electron capacity of a shell?

$$2n^2$$

Who proposed the Azimuthal Quantum Number ($l$)?

Sommerfeld (spelled 'Somer field' in text).

What are the subshell names corresponding to $l = 0, 1, 2, 3$?

$l = 0 \rightarrow s$ (spherical); $l = 1 \rightarrow p$ (principal); $l = 2 \rightarrow d$ (diffused); $l = 3 \rightarrow f$ (fundamental).

What is the formula for the total number of orbitals in a given shell?

$$n^2$$

What are the formulas for Radical (Radial) Nodes and Angular Nodes?

Radical (Radial) Nodes = $n - l - 1$; Angular Nodes = $l$.

Define the Aufbau Principle.

Electrons must be filled from lower energy orbitals to higher energy orbitals.

State Pauli's Exclusion Principle.

No two electrons in an atom can have the same set of four Quantum Numbers.

State Hund's Rule of Maximum Multiplicity.