Ionization Energy, Electron Affinity, and Electronegativity Trends in the Periodic Table

These flashcards cover key concepts from the lecture on ionization energy, electron affinity, and electronegativity, highlighting definitions, trends, and anomalies in the periodic table.

Ionization Energy

The energy required to remove an electron from an atom or ion.

Effective Nuclear Charge

The net positive charge experienced by valence electrons, increasing across a period in the periodic table.

Trend in Ionization Energy Across the Periodic Table

Ionization energy generally increases as you move from left to right across a period.

Trend in Ionization Energy Down the Periodic Table

Ionization energy generally decreases as you move down a group.

Anomaly in Ionization Energy (Beryllium vs. Boron)

Boron has a lower ionization energy than beryllium because it has an electron in a higher energy level (2p) that is easier to remove.

Electron Affinity

The energy change when a gaseous atom or ion gains an electron.

Exothermic Reaction

A reaction that releases energy, indicated by a negative change in enthalpy (ΔH).

Endothermic Reaction

A reaction that absorbs energy, indicated by a positive change in enthalpy (ΔH).

Trend in Electron Affinity Across the Periodic Table

Electron affinity becomes more negative (greater) as you move from left to right across a period.

Trend in Electron Affinity Down the Periodic Table

Electron affinity becomes less negative (lower) as you move down a group.

Electronegativity

A measure of an atom's ability to attract and hold onto electrons in a bond.

Paired Electrons in Orbitals

In some atoms, such as oxygen, paired electrons can lead to a lower ionization energy because they are less stable than unpaired electrons.

Coulomb's Law

A law describing the force between charged particles, where the force is proportional to the product of the charges and inversely proportional to the distance between them.

Melting Point and Ionic Bonds

Ionic compounds with smaller ions or greater charge typically have higher melting points due to stronger attractions.

Covalent Bonds

Bonds formed by sharing electrons between atoms, usually between nonmetals.

Ionic Bonds

Bonds formed by the complete transfer of electrons from one atom to another.