periodicity and trends in the periodic table

Electron Affinity

An atom’s ability to gain/attract electrons to form anions.

Ionic Bonds

Formation of ionic bonds as a result of an electron transfer.

Electronegativity

A measure of the tendency of an atom to attract electrons in covalent bonding.

Periodic Trends

Recurring trends observed in the properties of elements as you move across a period or down a group.

Atomic Radius

The size of an atom, which increases down a group due to the addition of electron shells.

Ionization Energy

The energy required to remove an electron from an atom.

Core Electrons

The inner electrons that shield the valence electrons from the nucleus.

Effective Nuclear Charge

The net positive charge experienced by outer electrons, influencing periodic trends.

Shielding Effect

The phenomenon where core electrons reduce the effective nuclear charge felt by valence electrons.

Trends Down a Group

Increases in atomic radius and decreases in ionization energy due to added electron shells.

Trends Across a Period

Decreases in atomic radius and increases in ionization energy due to increased nuclear charge.

Nonmetals and Metals Distinction

A pronounced difference in properties as electronegativity decreases across periods.

Valence Electrons

Electrons in the outer shell of an atom affecting its chemical behavior.

Atomic Size Increase Reasons

Increased energy levels and core electron shielding result in larger atomic radius.

Chemical Reactivity

Influenced by atomic radius, ionization energy, and electronegativity trends.

Covalent Bonding

The sharing of electrons between atoms, quantified by electronegativity.