Chapter 2: Electrons in Atoms & Ionizations

This set covers quantum numbers, electronic configuration rules (Aufbau, Pauli, Hund), orbital shapes, and periodic trends including atomic radius and ionization energy based on the Chapter 2 lecture notes.

The __________ states that you cannot determine the position and momentum of an electron at the same time.

Heisenberg Uncertainty Principle

The three-dimensional regions in space where there is a high probability of finding an electron are called __________.

orbitals

The formula used to calculate the total number of electrons in an orbit is __________.

$$2n^2$$

The Principal quantum number ($n$) represents the __________.

shell number or main energy level

The Angular momentum quantum number ($l$) defines the __________ of the subshell.

shape

The magnetic quantum number ($m_l$) can have integer values ranging from __________.

$-l$ to $0$ to $+l$

The Spin quantum number ($m_s$) has two possible values: __________ and __________.

$+1/2$ and $-1/2$

According to the __________, electrons enter the lowest available energy level first.

Aufbau principle

The __________ states that no two electrons in an atom can have the same four quantum numbers.

Pauli Exclusion principle

According to __________, electrons will try to remain unpaired when in orbitals of equal energy to reduce electrostatic repulsion.

Hund’s Rule of Maximum Multiplicity

An $s$ orbital has a __________ shape.

spherical

A $p$ orbital is described as having a __________ shape.

dumb-bell

The ground-state electronic configuration of Chromium ($Z=24$) is __________.

$$1s^2 2s^2 2p^6 3s^2 3p^6 3d^5 4s^1$$

The ground-state electronic configuration of Copper ($Z=29$) is __________.

$$1s^2 2s^2 2p^6 3s^2 3p^6 3d^{10} 4s^1$$

Across Period 3, the atomic radius tends to __________ as the nuclear charge increases.

decrease

__________ are atoms or ions that possess the same electronic configuration but different numbers of protons.

Isoelectronic species

The minimum energy needed to remove the outermost electron from a neutral atom in the gaseous state is the __________.

First Ionisation Energy

The first ionisation energy of aluminum is lower than magnesium because the electron is removed from a __________ sub-level, which is higher in energy than the $3s$ sub-level.

$$3p$$

The first ionisation energy of sulfur is lower than phosphorus due to __________ between paired electrons in the $3p$ orbital.

spin-pair repulsion

Successive ionisation energies for an element always increase, but a dramatic increase occurs when the first electron is removed from the __________.

noble-gas core