Atomic Orbitals, Electron Configurations & Electromagnetic Radiation

What does the Bohr model explain about electrons?

Electrons travel in fixed orbitals at specific distances from the nucleus.

What is the significance of emission spectra in atomic theory?

Emission spectra show that excited atoms emit light at specific energies, unique to each element.

What is the principal quantum number (n)?

n characterizes the energy of an electron in an orbital and can be any integer value ≥1.

What does the angular momentum quantum number (l) determine?

l determines the shape of an atomic orbital.

What is the Pauli Exclusion Principle?

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

What happens to an electron when it absorbs energy?

It moves to a higher orbital, increasing its energy.

What is the relationship between energy and the distance of an electron from the nucleus?

The energy of an electron in an orbital is proportional to its distance from the nucleus.

What is indeterminacy in quantum mechanics?

Indeterminacy means we cannot know both the position and velocity of a particle simultaneously.

What is a wavefunction?

The wavefunction, Ψ (psi), is the mathematical description of a particle in quantum mechanics.

What does the wavefunction squared, [Ψ(x, t)]², represent?

It represents the probability of finding a particle at location x at time t.

What is the role of quantum numbers in atomic orbitals?

Quantum numbers quantize the wavefunction, determining the size, shape, and orientation of orbitals.

What is the magnetic quantum number (ml)?

ml determines the orientation of an atomic orbital in space.

What is the connection between the Rutherford model and the Bohr model?

The Bohr model addresses the limitations of the Rutherford model by quantizing electron orbits.

What is the expected behavior of charged particles in motion according to classical physics?

They should emit radiation and lose energy, spiraling into the nucleus, which does not happen.

How does the Bohr model explain emission spectra?

Emission spectra are explained as the frequencies of light emitted when electrons transition between orbitals.

What is the effect of increasing the principal quantum number (n)?

Larger values of n correspond to bigger orbitals and increased energy.

What is the relationship between energy absorption and electron movement?

Absorption of light increases an electron's energy, moving it to a higher orbital.

What is the significance of the nucleus in the Rutherford model?

The nucleus contains the entire mass of the atom and is positively charged.

What does the term 'allowed quantum numbers' refer to?

Allowed quantum numbers are specific values that define the state of an electron in an atom.

What does the term 'valence electrons' refer to?

Valence electrons are the outermost electrons in an atom that participate in chemical bonding.

What is the purpose of quantum mechanics in understanding atomic behavior?

Quantum mechanics provides a framework for predicting the behavior of very small particles like electrons.

What values can the azimuthal quantum number (l) take?

Values from 0 to (n-1)

What shape do s orbitals have?

Spherical

At which principal quantum number (n) do p orbitals start to appear?

n = 2

How many p orbitals are present in each principal shell (n ≥ 2)?

Three p orbitals (px, py, pz)

What is the shape of d orbitals?

Mostly like balloons tied at their knots

At which principal quantum number do d orbitals start to appear?

n = 3

How many f orbitals are present in each principal shell (n ≥ 4)?

Seven f orbitals

What is the order of energy levels for orbitals?

s → p → d → f

What is the spin quantum number (ms) for an electron?

Can be +½ (spin up) or -½ (spin down)

What does the Pauli Exclusion Principle state?

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

What is the maximum number of electrons in an s subshell?

2 electrons

How many orbitals are in a p subshell?

3 orbitals

What is Hund's rule?

When filling degenerate orbitals, each orbital gets one electron before any get paired.

What are valence electrons?

Electrons in the highest principal shell.

What are core electrons?

Electrons in lower energy shells.

What happens to the energy levels of orbitals as n increases?

Energy levels increase; higher n means higher energy.

What is the significance of the Aufbau principle?

Electrons fill the lowest energy orbitals first.

What are the ml values for d orbitals?

-2, -1, 0, +1, +2

How many electrons can a p subshell hold?

6 electrons

What is the shape of f orbitals?

Complex shapes, often described as 'd orbitals TWO'

What is the relationship between n and l in quantum numbers?

l can take values from 0 to (n-1).

What is the maximum number of electrons in a d subshell?

10 electrons

What is the maximum number of electrons in an f subshell?

14 electrons

What does it mean for orbitals to be degenerate?

Orbitals with the same energy.

What is the difference between full and abbreviated electron configurations?

Full configuration lists all electrons in every subshell, while abbreviated uses the nearest noble gas to represent core electrons.

How do main group elements determine their number of valence electrons?

Each column from left to right in the periodic table corresponds to one additional valence electron.

What is the effective nuclear charge?

The net positive charge experienced by valence electrons, considering the distance from the nucleus and shielding by other electrons.

What happens to atomic radius as you move down a group in the periodic table?

Atomic radius increases due to higher energy levels and additional electron shells.

What is the trend in atomic radius across a period?

Atomic radius decreases as effective nuclear charge increases, pulling electrons closer to the nucleus.

How do cations compare in size to their neutral atoms?

Cations are smaller than their neutral atoms because they lose electrons and empty their highest energy shell.

How do anions compare in size to their neutral atoms?

Anions are larger than their neutral atoms because they gain electrons, increasing electron-electron repulsion.

What is ionization energy?

The minimum energy required to remove an electron from an atom.

What is the significance of noble gas configurations?

Noble gases have full valence shells, making them stable and non-reactive.

What do alkali metals tend to do to achieve noble gas configurations?

They tend to lose one electron to form +1 cations.

What do halogens tend to do in reactions with metals?

They tend to gain an electron to form -1 anions.

What is the trend in ionic radius for ions in a group?

Ionic radius increases down the group due to higher valence shells.

What is the relationship between effective nuclear charge and atomic size?

Higher effective nuclear charge results in smaller atomic size due to stronger attraction between nucleus and electrons.

What is the atomic radius trend for transition metals?

Atomic radius increases down the group and remains nearly constant across the period.

What is the effect of electron shielding on effective nuclear charge?

Electrons in lower shells shield valence electrons from the full effect of the nuclear charge.

What is the first ionization energy (IE1)?

The energy required to remove an electron from a neutral atom.

What is the second ionization energy (IE2)?

The energy required to remove an electron from a 1+ cation.

What trend is observed in first ionization energy across a period?

First ionization energy generally increases across a period due to increased effective nuclear charge.

What trend is observed in first ionization energy down a group?

First ionization energy generally decreases down a group as electrons are further from the nucleus.

How does the reactivity of alkali metals relate to first ionization energy?

Heavier alkali metals have lower first ionization energies, making them more eager to give up electrons.

Why are noble gases reluctant to give up electrons?

Noble gases have a stable electron configuration, making them very stable and unreactive.

What is electron affinity?

The energy released when a neutral atom gains an electron, generally defined as exothermic.

How does electron affinity change across a period?

Electron affinity generally increases across a period, meaning more energy is released.

What are the exceptions to the trend in ionization energy?

There are exceptions from 2A to 3A and from 5A to 6A due to the stability of fully or half-filled subshells.

What happens to the energy required for successive ionization energies?

Each successive electron removed requires more energy, with larger increases for core electrons.

What is the wave/particle duality of light?

Light exhibits properties of both particles (photons) and waves (oscillations in electric and magnetic fields).

What is a photon?

A photon is a discrete packet of light energy that has a specific energy and behaves like a particle.

What is the amplitude of a light wave?

The amplitude is the size of the fluctuation in the electric and magnetic fields, measured from the origin to a peak or trough.

What is the wavelength of light?

The wavelength (λ) is the distance between successive oscillations, traditionally measured in nanometers (nm).

What is frequency in the context of light?

Frequency (ν) is how often the peaks of a wave occur, measured in hertz (Hz) or per second (s-1).

How are wavelength and frequency related?

Wavelength and frequency are inversely related; as wavelength increases, frequency decreases and vice versa.

What are the categories of light based on wavelength?

From lowest to highest energy: Radio, Microwave, Infrared, Visible light, Ultraviolet, X-ray, Gamma.

What determines the brightness of light?

Brightness is determined by the amplitude of the light wave, which indicates the number of photons present.

What is the relationship between energy and frequency of a photon?

The energy of a photon is directly proportional to its frequency; higher frequency means higher energy.

How do you calculate the energy of a photon given its frequency?

Energy (E) can be calculated using the formula E = hν, where h is Planck's constant.

What is the significance of black-body radiation?

Black-body radiation describes how objects emit light based on their temperature, primarily in the infrared range.

What are the units for measuring wavelength?

Wavelength is measured in meters (m), centimeters (cm), or nanometers (nm), with 1 nm = 10^-9 m.

What happens to light when it passes through different media?

Light can refract, reflect, or be absorbed depending on the medium it encounters.

What is the role of interference in light waves?

Interference occurs when light waves overlap, leading to patterns of constructive and destructive interference.

What is the significance of the ionosphere for radio waves?

The ionosphere reflects radio waves, allowing them to travel long distances beyond the horizon.

How does the energy of light relate to its color?

The energy difference between electronic orbitals in atoms corresponds to specific visible wavelengths, which determine color.