Periodic Table and Electronic Configuration

Vocabulary flashcards covering the historical development, periodic law, shell configurations, groups, and periods from Chapter 10 of the lecture notes.

Mendeleev's Periodic Table

The first periodic table, constructed with elements arranged in increasing order of relative atomic mass, which contained many gaps for undiscovered elements.

Modern Periodic Table

A periodic table where elements are arranged in increasing order of atomic numbers, differing from Mendeleev's periodic table.

Modern Periodic Law

The law stating that the physical and chemical properties of elements are a periodic function of their atomic numbers.

Electronic Configuration

The arrangement of electrons derived from the atomic number of an element, which serves as the key to the periodicity of elements.

Shell

An orbit or energy level in which electrons revolve, where electrons close to the nucleus possess less energy than electrons far away.

Principal Shells

The energy levels labeled K, L, M, N, O…, which correspond to energy levels 1, 2, 3, 4, and 5.

Maximum Electrons in a Shell Formula

The mathematical expression $2n^2$ used to determine the maximum number of electrons a shell can hold, giving $2(1)^2 = 2$ for the K shell and $2(2)^2 = 8$ for the L shell.

Groups

Vertical columns in the periodic table numbered from 0 to 7, where elements in the same group possess the same number of valence electrons.

Periods

Seven horizontal rows in the periodic table numbered 1 to 7, where elements in the same period have the same number of electron shells.

Inner Transition Elements

The collective term for the elements of the lanthanide and actinide series located in Period 6 and Period 7.