Periodic Table and Atomic Trends

These flashcards cover key definitions and concepts related to the periodic table, atomic trends, and the properties of elements as discussed in the lecture notes.

Periodic Table

A table proposed in 1869 by Dmitri Mendeleev that displays elements in a systematic arrangement based on increasing atomic mass and properties.

Atomic Size (Radius)

The size of an atom, which increases down a group and decreases across a period.

Ionization Energy (IE)

The amount of energy required to remove an electron from an atom, which decreases down a group and increases across a period.

Electron Affinity (EA)

The change in energy when an electron is added to an atom, becoming more negative across a period and more positive down a group.

Electronegativity

The ability of an atom in a molecule to attract shared electrons, which decreases down a group and increases across a period.

Atomic Radius Trend

The atomic radius increases down a group due to increasing energy levels and decreases across a period due to increased proton pull.

Ionic Radius

The radius of an ion; nonmetal ions are larger than their atomic radius, while metal ions are smaller.

First Ionization Energy

The amount of energy required to remove the first electron from an atom.

Electron Affinity (Negative Value)

A negative EA value indicates that energy is released when an atom gains an electron.

Electronegativity Trend

As you move down a group, electronegativity decreases; as you move across a period, electronegativity increases.