Periodic Trends and Atomic Properties

Flashcards covering key vocabulary, definitions, and periodic trends including atomic radius, ionization energy, electron affinity, and ion formation.

Atomic Radius

One-half the distance between the nuclei of two atoms of the same element,

Picometer ($\text{pm}$)

The unit of measurement typically used for atomic radius, equal to $1 \times 10^{-12}\,\text{m}$.

Hydrogen and Helium (Atomic Radius)

The smallest atoms on the periodic table, each possessing an atomic radius of about $30\,\text{pm}$.

Francium (Atomic Radius)

The largest atom on the periodic table, having an atomic radius of about $260\,\text{pm}$.

Effective Nuclear Charge ($Z_{\text{eff}}$)

The principle explaining periodic trends that represents the net positive charge experienced by valence electrons,

Ion

An atom or group of atoms that carries a positive or negative charge.

Cation

An ion formed when an atom loses one or more electrons, resulting in a net positive charge

Anion

An ion formed when an atom gains one or more electrons, resulting in a net negative charge

Ionization Energy

The energy required to remove the outermost electron from the ground state of a gaseous atom.

Mole ($\text{mol}$)

An amount of matter equal to the atomic mass of an element expressed in grams.

Coulomb's Law

A principle stating that the closer an electron is to the nucleus, the stronger the force of attraction

First Ionization Energy ($I_1$)

The energy required to remove the outermost electron from an atom to form an ion.

Second Ionization Energy ($I_2$)

The energy needed to remove the second electron from an ion.

Electron Affinity

The energy change that occurs when an atom gains an electron;

Metallic Character

The tendency of an element to lose electrons and form cations,

Nonmetallic Character

The tendency of an element to gain electrons and form anions,

Periodic Trends

Predictable patterns across the periodic table

Group 1 Metals (Common Ion Charge)

Metals that lose one valence electron to form cations with a $1+$ charge.

Group 2 Metals (Common Ion Charge)

Metals that lose two valence electrons to form cations with a $2+$ charge.

Group 17 Nonmetals (Common Ion Charge)

Nonmetals that gain one electron to form anions with a $1-$ charge.