Chemistry and Energy Foundations Review

Vocabulary flashcards covering atomic structure, electron configurations, isotopes, periodic trends, and chemical thermodynamics based on the lecture transcript.

Atomic number

The property equal to the number of protons in an atom, which also determines the number of electrons in a neutral atom.

Neutral atom

An atom that has no overall charge, requiring an equal number of protons (each carrying a $+1$ charge) and electrons (each carrying a $-1$ charge).

Electron configuration of aluminium

The arrangement of electrons for an aluminium atom with atomic number $13$ ($13$ protons and $13$ electrons), given as $1s^2\,2s^2\,2p^6\,3s^2\,3p^1$.

Electron configuration of potassium ($Z = 19$)

The electron configuration recorded in the notes for potassium ($Z = 19$), written as $1s^2\,2s^2\,2p^6\,3s^2\,3p^6\,3d^1$.

$s$ sublevel electron capacity

The maximum number of electrons that can occupy an $s$ sublevel, which is $2$.

$p$ sublevel electron capacity

The maximum number of electrons that can occupy a $p$ sublevel, which is $6$.

$d$ sublevel electron capacity

The maximum number of electrons that can occupy a $d$ sublevel, which is $10$.

$f$ sublevel electron capacity

The maximum number of electrons that can occupy an $f$ sublevel, which is $14$.

Sublevel filling order

The usual filling order of atomic sublevels: $1s$, $2s$, $2p$, $3s$, $3p$, $4s$.

Orbital capacity

The maximum number of electrons that can occupy a single orbital, which is $2$.

Sulphur

The chemical element containing $16$ electrons with the electron configuration $1s^2\,2s^2\,2p^6\,3s^2\,3p^4$.

Isotope

Any form of a chemical element which has the same number of protons (and electrons) in the nucleus but a different number of neutrons, resulting in a different mass number.

Chlorine-35 and chlorine-37

Isotopes of chlorine that have the same number of protons (and electrons if neutral) determining the element they are, but differ in their atomic mass and number of neutrons.

Chemical properties of isotopes

The similar chemical behavior observed among isotopes of an element because they possess the same number of protons and electrons, and chemical reactions involve electron arrangement rather than neutrons.

Relative atomic mass (RAM)

The average mass of an element's isotopes calculated using the formula $\text{RAM} = \frac{\sum (\text{isotope mass} \times \text{abundance})}{100}$.

Atomic radius

The distance from the centre of an atom's nucleus to its outermost electron shell.

Period trend in atomic radius

The periodic trend where atomic radius decreases as you move horizontally from left to right across a period.

Group trend in atomic radius

The periodic trend where atomic radius increases as you move vertically down a group because the electrons increase.

Atomic radius comparison: Potassium ($K$) vs. Lithium ($Li$)

Potassium ($K$) has the larger atomic radius because, although both are in Group 1, potassium is located further down the periodic table.

Law of Conservation of Energy

A fundamental law stating that energy cannot be created or destroyed; it can only change form or transfer from one object to another.

First Law of Thermodynamics

The thermodynamic law defined as the law of conservation of energy.

Endothermic reaction

A reaction where $\Delta H$ is positive ($\Delta H > 0$), energy enters causing temperature to decrease, and the total chemical energy of the product is greater than the reactant.

Exothermic reaction

A reaction where energy is released and transferred from the system to the surroundings causing heat to increase, characterized by $\Delta H < 0$ and product chemical energy less than reactant chemical energy.

Bond breaking

A chemical process that requires energy because the chemical bonds that hold energy together must be repelled against.

Enthalpy change from bond enthalpies ($\Delta H$)

The net enthalpy change of a reaction calculated as $\Delta H = \text{Energy to break bonds} - \text{energy released}$.