Periodic_Table_Trends

Periodic Trends

The patterns observed in atomic properties such as atomic radius, ionization energy, and electronegativity across different elements.

Atomic Radius

The size of an atom; it depends on the number of electron shells and the number of protons in the nucleus.

Ionization Energy

The energy required to remove an electron from an atom.

Electronegativity

The measure of an atom's ability to attract and hold onto electrons.

Effective Nuclear Charge

The net positive charge experienced by valence electrons, calculated as the number of protons minus the number of inner electrons.

Trend (Atomic Radius)

Increases down a group and decreases across a period in the periodic table.

Shielding Effect

The phenomenon where inner-shell electrons reduce the effective nuclear charge felt by outer-shell electrons.

Patterns in Ionization Energy

Ionization energy increases across a period and decreases down a group due to changes in atomic size and effective nuclear charge.

Successive Ionization Energies

The energy required to remove each subsequent electron from an atom; these energies increase due to greater attraction between the nucleus and remaining electrons.

Electronegativity Trend

Electronegativity increases across a period and decreases down a group in the periodic table.

Trends in Properties Across a Period

As one moves across a period in the periodic table, atomic radius decreases, electronegativity increases, and ionization energy increases.

Trends in Properties Down a Group

As one moves down a group in the periodic table, atomic radius increases, electronegativity decreases, and ionization energy decreases.

Core Charge

The effective nuclear charge felt by the valence electrons, determined by the number of protons minus the shielding effect of inner electrons.

Valence Electrons

Electrons in the outermost shell of an atom, which are involved in chemical bonding.

Ionic Radius

The radius of an ion; it can differ from the atomic radius depending on the gain or loss of electrons.

Group 1 Elements

Elements known to have low first ionization energies, making them more reactive.

Group 18 Elements

Noble gases with complete outer shells, having high ionization energies and low reactivity.

Nuclear Charge

The total charge of the nucleus, equal to the number of protons.

Electron Affinity

The amount of energy released when an electron is added to a neutral atom.

Trends in Group Elements

Show consistent patterns across periods and groups regarding atomic properties such as size and reactivity.