CHM 100 DR. K GRANT Unit 3 Pt2 Atoms and the Periodic Table Electron Configurations

Flashcards covering the quantum mechanical model, electron energy levels, sublevels, orbitals, electron configuration rules, and their relation to the periodic table and valence electrons.

What primarily determines the properties of elements?

The arrangement of electrons in their atoms.

What model helps us understand the electronic structure of atoms?

The quantum mechanical model.

Who developed the quantum mechanical model?

Erwin Schrödinger.

According to the quantum mechanical model, what two properties do electrons possess?

Particle-like and wavelike properties.

What does it mean for the energy of an electron to be 'quantized'?

Electrons can have only specific energy values.

What is a 'principal energy level' (or 'shell') in an atom?

A grouping of electrons in an atom according to energy, designated by the principal quantum number (n).

How does the energy of an electron change as its principal energy level (n) increases?

The energy of the electron increases as n increases, meaning it is farther away from the nucleus.

What is the maximum electron capacity for the first four principal energy levels (n=1, 2, 3, 4)?

n=1: 2 electrons; n=2: 8 electrons; n=3: 18 electrons; n=4: 32 electrons.

How many sublevels are there in an energy level equal to its principal quantum number (n)?

The number of sublevels in an energy level is equal to its principal quantum number (n).

What are the four types of sublevels, in order of increasing energy?

s, p, d, and f (s < p < d < f).

What is an 'orbital'?

A three-dimensional volume in which electrons have the highest probability of being found.

What does the Pauli exclusion principle state about electrons in an orbital?

Each orbital can hold a maximum of two electrons, which must have opposite magnetic spins.

How many orbitals are in each of the s, p, d, and f subshells?

s subshell has 1 orbital; p subshell has 3 orbitals; d subshell has 5 orbitals; f subshell has 7 orbitals.

What is the maximum number of electrons that can be held in an f sublevel?

Since an f sublevel has 7 orbitals, and each orbital holds 2 electrons, it can hold a maximum of 14 electrons.

What shape do s orbitals have?

s orbitals are spherical.

What shape do p orbitals have?

p orbitals are roughly dumbbell shaped.

What is an electron configuration?

The exact arrangement of electrons in an atom's shells and subshells.

What are orbital diagrams used for?

To show how electrons are arranged in the orbitals of an atom, indicating their placement and spin.

What is the Aufbau Principle?

Electrons occupy the lowest energy orbitals available first.

What is Hund's Rule?

When filling degenerate orbitals (orbitals of the same energy), each orbital is first half-filled with one electron before any orbital is completely filled by the addition of a second electron.

How are the electron configurations of elements related to their positions on the periodic table?

Different sections or blocks (s, p, d, f) of the periodic table correspond to the sublevels being filled with electrons.

Which groups on the periodic table correspond to the s-block elements?

Groups 1A (1) and 2A (2).

Period 4 group 7A (Group 17) corresponds to which element, and what is its electron configuration?

The element is Bromine (Br). Its electron configuration is 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁵.

What is a 'valence shell'?

The outermost electron shell of an atom.

What is a 'valence electron'?

An electron located in the valence shell of an atom.

For representative elements (Groups 1A-8A), how does the group number relate to the number of valence electrons?

For representative elements, the group number is equal to the number of valence electrons.

What is a Lewis Electron-dot symbol?

An atomic symbol with dots placed around it to indicate the number of valence electrons.