GenChem- Atomic Structure, Quantum Numbers, and Electron Configuration

What is matter comprised of?

Everything around us, consisting of extremely small units called atoms.

What is an element?

Matter composed entirely of one type of atom (e.g., gold or oxygen gas).

What is a molecule?

Two or more atoms bonded together (e.g., O2).

What is a compound?

Molecules with more than one type of atom (e.g., ammonia or water).

What are the three subatomic particles of an atom?

Protons, neutrons, and electrons.

Where do protons reside in an atom?

In the nucleus.

What is the charge and mass of a proton?

Positive charge, mass of 1 amu/dalton.

Where do neutrons reside in an atom?

In the nucleus.

What is the charge and mass of a neutron?

No charge and mass of 1 amu/dalton.

What is the mass and charge of an electron?

Negligible mass and negative charge.

What is the electron cloud?

A visualization of the probable location of electrons around the nucleus.

What are orbitals?

Regions of space where electrons are likely found.

What do dim electrons closer to the nucleus have in terms of energy?

Lowest energy and highest stability.

What are valence electrons?

The electrons in the outermost shell that primarily interact and react with other atoms.

What defines the unique configurations of atoms?

The unique configurations of protons and neutrons orbited by electrons.

What defines the atomic number (Z)?

The number of protons in an atom.

What is the mass number (A)?

The total number of protons and neutrons in an atom.

What are isotopes?

Variations of the same element that have different numbers of neutrons.

Give an example of two isotopes of Carbon.

Carbon-12 (6 protons, 6 neutrons) and Carbon-13 (6 protons, 7 neutrons).

What is atomic weight?

The weighted average of an atom accounting for all possible isotopes.

What is molecular weight?

The weight of a molecule, not to be confused with atomic weight.

What happens when atoms gain or lose electrons?

They become ions.

What are cations?

Positively charged ions.

What are anions?

Negatively charged ions.

What are polyatomic ions?

Ions composed of more than one atom.

What does the nomenclature rule state for elements having more than one oxidation state?

Use Roman numerals for charges.

What suffix do anions typically end with?

-ide.

What suffixes are used for oxyanions?

-ite (fewer oxygens) and -ate (more oxygens).

What does atomic theory state?

All matter consists of tiny units called atoms.

How do electrons behave in relation to the atomic nucleus?

They orbit the nucleus in shells.

What happens to energy when electrons move between energy levels?

Energy changes occur in discrete amounts.

What principle does the Bohr model start with?

Uses hydrogen as the simplest element.

How are the energy levels in the Bohr model labeled?

Labeled as n = 1, 2, 3, etc.

What does atomic emission spectrum represent?

Pattern of lines when an electron falls to a lower energy level.

What does atomic absorption spectrum represent?

Lines when an electron moves to a higher energy level.

What does the Rydberg Formula calculate?

The amount of energy emitted or absorbed when an electron moves between levels.

What principle states you cannot precisely determine both the position and momentum of an electron at a given time?

Heisenberg Uncertainty Principle.

What do electron orbitals indicate?

Regions where electrons are likely to be found.

What do quantum numbers describe?

Describe an electron's shell, subshell, orientation, and spin.

What is the Pauli exclusion principle?

No two electrons in an atom can have the same set of quantum numbers.

What does the principal quantum number (n) describe?

The energy level of an electron.

What correspond does the angular momentum quantum number (l) have?

Corresponds to the shape of the orbital.

What does the magnetic quantum number (M sub-L) indicate?

The spatial orientation of the orbital.

What does the spin quantum number (M sub-S) specify?

The direction of the electron's spin.

What is the Aufbau principle?

Electrons fill the lowest energy orbitals first before filling higher ones.

How does Hund's Rule apply to electron configuration?

Electrons fill each orbital of a subshell singly with parallel spins until they must pair.

What is meant by 'half-filled' and 'fully-filled' subshells in terms of stability?

They are more stable configurations that can lead to exceptions in filling order.

How does the periodic table help in determining electron configurations?

It can be divided into blocks that correspond to the subshells (s, p, d, f).

What happens to the configuration of cations compared to their neutral parent atom?

They have one less electron.

What happens to the configuration of anions compared to their neutral parent atom?

They have one more electron.

In transition elements, how does the energy levels of subshells fluctuate?

The relative energy levels fluctuate as they are filled.

What is the relationship between orbitals and stabilization in electron configuration?

Half-filled or fully filled subshells are more stable.

In the context of nomenclature for ionic compounds, what is true for monatomic anions?

They typically end in -ide.

What is the formula for calculating the energy difference when an electron moves between energy levels?

Energy difference equals Rydberg constant times (1/initial level squared - 1/final level squared).

What explains the stability of atoms based on electron configurations?

The principles of the Aufbau and Pauli exclusion principle.