Chapter 2 Atomic Structure and Electronic Configuration

Flashcards for reviewing atomic structure, electronic configuration, and related concepts.

What are the three subatomic particles that compose an atom?

Protons, Neutrons, and Electrons

What is the charge of a proton?

Positive (+)

What is the charge of a neutron?

Neutral

What is the charge of an electron?

Negative (-)

What is the Atomic Number (Z)?

The number of protons in the nucleus of an atom.

What is the Mass Number (A)?

The total number of protons and neutrons in the nucleus of an atom (P + n).

How do you calculate the number of neutrons (n)?

Mass Number (A) – Atomic Number (Z)

In a neutral atom, how does the number of protons relate to the number of electrons?

Number of protons = Number of electrons

What is an ion?

An atom or molecule that has gained or lost electrons, giving it an electrical charge.

What is a cation?

A positively charged ion formed when an atom loses electrons.

What is an anion?

A negatively charged ion formed when an atom gains electrons.

What are isotopes?

Atoms of the same element that have different numbers of neutrons (same atomic number, different mass number).

Name the isotopes of hydrogen.

Protium (¹H), Deuterium (²H), and Tritium (³H)

What does the Principal Quantum Number (n) indicate?

Main energy levels (n = 1, 2, 3, 4…)

What is an atomic orbital?

A region in space around the nucleus of an atom where there is a high probability of finding an electron.

What does the Azimuthal Quantum Number (ℓ) indicate?

The shape of the orbital sublevels (ℓ = 0, 1, …, (n-1))

What are the sublevels corresponding to ℓ = 0, 1, 2, and 3?

ℓ=0 (s), ℓ=1 (p), ℓ=2 (d), ℓ=3 (f)

What does the Magnetic Quantum Number (mℓ) indicate?

The orientation of the orbital in space (integer values from -ℓ to +ℓ, including zero).

How many orbitals are in s, p, d, and f sublevels, respectively?

s has 1 orbital, p has 3 orbitals, d has 5 orbitals, and f has 7 orbitals.

What does the Electron Spin Quantum Number (ms or s) indicate?

The direction in which an electron spins in an orbital (clockwise or counterclockwise).

What are the possible values of ms?

-1/2 and +1/2

What is the Aufbau principle?

Electrons enter the orbitals in order of ascending energy.

What is electron configuration?

How the electrons are distributed among the various atomic orbitals in an atom.

What is Hund's Rule?

When filling orbitals of equal energy, electrons will try to remain unpaired.

What is Pauli’s Exclusion Principle?

No two electrons in the same atom can have the same set of four quantum numbers (n, ℓ, mℓ, ms).

Define a completely filled orbital.

An orbital that contains two electrons.

Define a half-filled orbital (singly occupied orbital).

An orbital that contains one electron.

Define a vacant orbital.

An orbital that contains no electrons.

What is the real electronic configuration of Chromium (24Cr)?

1s2 2s2 2p6 3s2 3p6 4s1 3d5

What is the real electronic configuration of Copper (29Cu)?

1s2 2s2 2p6 3s2 3p6 4s1 3d10

What is a valence shell?

The outermost electron shell of an atom containing the valence electrons.

What are valence electrons?

Electrons in the outermost shell (valence shell) of an atom that can participate in forming chemical bonds.

What is a transition metal?

A metal whose atom has an incomplete d subshell or which can give rise to cations with an incomplete d subshell.

When forming ions, from which orbitals are electrons removed first in transition metals?

Electrons are removed from the ns orbital before the (n-1)d orbitals.