Periodicity and Building Up of the Periodic Table

These flashcards cover key vocabulary and concepts related to periodicity and the building up of the periodic table as discussed in the lecture.

Periodic Law

The properties of the elements are the periodic function of their atomic masses.

Modern Periodic Law

The physical and chemical properties of elements are the periodic functions of their atomic numbers.

Main Group Elements

The s- and p- block elements in the periodic table.

Atomic Radius

The distance from the centre of the nucleus to the outermost shell of the electrons in an atom.

Covalent Radius

Half the inter-nuclear distance between two similar atoms that are covalently bonded.

Van der Waals' Radius

Half the inter-nuclear separation between two similar adjacent atoms in solid state.

Electronegativity

The relative tendency of an atom in a molecule to attract shared pair of electrons.

Ionisation Enthalpy

The molar enthalpy change accompanying the removal of an electron from a gaseous atom.

Electron Gain Enthalpy

The change in enthalpy when an isolated gaseous atom adds an electron to form an anion.

Valence Electrons

Electrons present in the outermost shell of an atom.

Valency

The number of electrons an atom loses, gains, or shares to achieve a noble gas configuration.

Electropositivity

The tendency of an element to lose electrons and form positive ions.

Reactivity of Metals

The tendency of an element to lose electrons; decreases from left to right in a period.

Reactivity of Non-Metals

The tendency of an element to gain electrons; increases from left to right in a period.

Solubility of Alkali Metal Carbonates

Increases down the group from Lithium to Caesium.

Anomalous Properties of Second Period Elements

Attributed to small size, large charge/radius ratio, and high electronegativity.