General Chemistry II: Comparative Chemistry of Groups IA, IIA, and IVA

This set of vocabulary flashcards covers key periodic trends, properties of alkali and alkaline earth metals, and the characteristics of the carbon group based on the CHM102 lecture notes.

Alkali metals

Group IA elements (Li, Na, K, Rb, Cs, Fr) characterized by softness, low density, low melting points, and the readiness to form $M^+$ ions.

Periodic trend

A regular pattern or change in a property of elements as one moves across a period or down a group in the Periodic Table.

Shielding

The reduction in effective nuclear attraction on valence electrons caused by inner-shell electrons.

Ionisation energy

The energy required to remove one electron from a gaseous atom to form a gaseous cation.

Electronegativity

The tendency of an atom in a molecule to attract shared electrons towards itself.

Oxidation state

A bookkeeping number representing the degree of electron loss or gain by an atom in a compound relative to its elemental state.

Diagonal relationship

A similarity in properties between elements diagonally adjacent in the Periodic Table, such as the relationship between Li and Mg.

Charge density

The concentration of charge over a specific volume; for example, the $Li^+$ ion has its $+1$ charge concentrated over a tiny volume due to its small radius.

Polarising power

The ability of a small cation with a high electric field to distort the electron cloud of large anions (like $I^-$ or $CO_3^{2-}$), leading to increased covalent character.

Alkaline earth metals

Group IIA elements (Be, Mg, Ca, Sr, Ba, Ra) that form $+2$ ions and are generally less reactive than Group IA metals.

Basicity

The ability of a substance to accept protons ($H^+$) or produce hydroxide ions ($OH^-$) in water.

Precipitate

An insoluble solid that forms from a solution during a chemical reaction, such as $BaSO_4(s)$.

Metallic character

The tendency of an element to lose electrons and form cations; this property increases down a group.

Catenation

The ability of atoms of the same element, such as carbon, to bond to each other to form long chains and rings.

Inert pair effect

The tendency of the outermost s-electron pair ($ns^2$) in heavier p-block elements to remain non-bonding, making lower oxidation states (like Pb(II)) more stable than higher ones.

Amphoteric

A substance's ability to react as either an acid or a base, seen in Group IVA oxides like SnO and PbO.

Hydrolysis

A chemical reaction in which water breaks chemical bonds, often producing acidic or basic products.

Superoxides

Oxygen-containing anions such as $KO_2$ formed by heavier alkali metals where larger cation sizes stabilize larger anions.