Quantum Numbers, Electron Configuration, and Atomic Structure: Key Concepts for Chemistry

What are quantum numbers?

Numbers that describe the location and energy of an electron in an atom.

Which quantum number shows the shape of the atomic orbital?

The angular momentum quantum number (l).

Which orbital has a spherical shape?

The s orbital.

Which orbital has a figure eight shape?

The p orbital.

Which quantum number represents the energy level of the orbital?

The principal quantum number (n).

Which quantum number represents the orientation of an orbital in space?

The magnetic quantum number (ml).

Which quantum number represents the direction of the spin on an electron?

The spin quantum number (ms).

How many orbital diagram boxes are in a p orbital?

Three.

What is an example of an orbital that cannot exist?

2d (because d orbitals start at n = 3).

If the first electron in an orbital is spinning upward, how will the second electron spin?

Downward (opposite spin).

How many electrons can occupy a d orbital?

Ten.

The electronic configuration of the element whose atomic number is 26 is:

1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d⁶ (Iron, Fe).

The following electron configuration 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p¹ corresponds with which element?

Gallium (Ga).

Write the short-hand electron configuration for Potassium and for Iron.

K: [Ar] 4s¹; Fe: [Ar] 4s² 3d⁶.

Absorption is when an electron gains energy and moves to a higher or lower energy level?

Moves to a higher energy level.

What happens during emission of energy by an electron?

The electron loses energy and moves to a lower energy level.

A photon is defined as...

A packet (quantum) of light energy.

What types of things behave as both a particle and a wave?

Both electrons and light.

What is the Heisenberg Uncertainty Principle.

This states that it is impossible to determine exactly both position and velocity simultaneously of an electron.

The lowest energy state of an atom or other particle is called the...

Ground state.

The force between two or more charged bodies is called...

Electrostatic forces.

This states that electrons occupy the lowest energy level first that can receive the electron.

Aufbau Principle.

This states that no two electrons in the same atom can have the same 4 quantum numbers.

Pauli Exclusion Principle.

This states that every orbital in a subshell is singly occupied before any are doubly occupied.

Hund's Rule.

What is the maximum number of electrons that an orbital can possess?

Two.

What is the maximum number of electrons that can occupy the 2nd energy level?

Eight.

As frequency increases, the amount of energy of a wave increases or decreases?

Increases.

Write the full electron configuration for Scandium.

1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹.

Write the full electron configuration for Arsenic.

1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p³.

Draw the orbital diagram for Phosphorus.

1s² 2s² 2p⁶ 3s² 3p³ (three unpaired electrons in p orbitals).

Draw the orbital diagram for Chromium.

[Ar] 4s¹ 3d⁵ (half-filled stability).

Write the short-hand electron configuration for Nickel.

[Ar] 4s² 3d⁸.

Write the short-hand electron configuration for Fluorine.

[He] 2s² 2p⁵.

Using Coulomb's law, explain what happens when an electron moves closer to the nucleus.

The attractive force increases; moving farther decreases the force.

What are valence electrons?

Electrons in the outermost energy level; shown after the noble gas in shorthand notation.

When atoms form ions, does the radius increase or decrease?

Increases for anions, decreases for cations.

Review the location, charge, and mass of subatomic particles.

Proton: nucleus, +1, 1 amu; Neutron: nucleus, 0, 1 amu; Electron: outside nucleus, -1, ~0 amu.