Periodic Table and Periodic Properties

Vocabulary flashcards covering key periodic classification laws, groups, periodic trends, and terminology from the lecture.

Dobereiner's Triads

Groups of three elements arranged in increasing order of atomic masses where the atomic mass of the middle element is approximately the average of the atomic masses of the other two elements.

Newlands Law of Octaves

Principle stating that when elements are arranged in increasing order of atomic masses, every eighth element shows resemblance in physical and chemical properties to the first element, similar to musical notes.

Mendeleev's Periodic Law

Law stating that the physical and chemical properties of elements are periodic functions of their atomic masses.

Modern Periodic Law

Law stating that the physical and chemical properties of elements are periodic functions of their atomic numbers.

Groups

The 18 vertical columns in the periodic table containing elements that share similar outer electronic configurations and chemical properties.

Periods

The 7 horizontal rows in the periodic table, where each period number corresponds to the total number of electron shells in an atom.

Diagonal Relationship

The similarity in physical and chemical properties shown between two diagonally adjacent elements in the second and third periods of the periodic table, such as $\text{Li}$ and $\text{Mg}$.

Bridge Elements

Elements of the second period that connect their own group diagonally to the next group in the periodic table.

Typical Elements

Elements of the third period ($\text{Na}$, $\text{Mg}$, $\text{Al}$, $\text{Si}$, $\text{P}$, $\text{S}$, and $\text{Cl}$) that summarize and represent the general properties of their respective main groups.

Alkali Metals

Highly reactive electropositive Group 1 metals (from lithium to francium) that form soluble bases, have a valency of 1, and act as strong reducing agents.

Alkaline Earth Metals

Group 2 metals (from beryllium to radium) found in the Earth's crust that have a valency of 2, donate electrons, and form electrovalent compounds.

Halogens

Highly reactive electronegative Group 17 non-metals (from fluorine to astatine) that accept electrons, have a valency of 1, and form covalent compounds.

Noble Gases

Chemically stable or nonreactive Group 18 monoatomic elements with a valency of zero and completely filled outer electron shells.

Effective Nuclear Charge

The net positive attraction force exerted by the nucleus on the outer valence electrons of an atom.

Atomic Size

The distance from the center of the nucleus to the outermost valence shell of an atom.

Metallic Character

The tendency of an atom to lose electrons and form a positively charged cation.

Non-metallic Character

The tendency of an atom to gain electrons and convert itself into a negatively charged anion.

Electronegativity

The tendency of an atom to attract the shared pair of electrons toward itself within a molecule.

Electron Affinity

The amount of energy released when an atom in the gaseous state accepts an electron to form a negatively charged anion.

Ionization Potential

The amount of energy required to remove an electron from an isolated neutral gaseous atom to form a positively charged cation.

Transuranic Elements

Synthetic or man-made elements having an atomic number greater than 92 ($Z > 92$).