Fluorine is the most electronegative element, meaning it has the strongest attraction for electrons in a chemical bond.

Sodium and chlorine form an ionic bond, where sodium donates an electron to chlorine, resulting in oppositely charged ions.

Hemoglobin is a coordination complex, where an iron ion is surrounded by a porphyrin ring and other ligands.

Atomic size generally decreases across a period from left to right due to increasing nuclear charge and the same number of electron shells.

Hydrochloric acid is a strong acid, meaning it completely dissociates in water to form hydrogen ions (H+) and chloride ions (Cl-).

The compound with the formula $Fe_2O_3$ is called iron(III) oxide, also known as ferric oxide.

Helium, neon, argon, and krypton are all noble gases, characterized by their lack of reactivity due to their full valence electron shells.

Oxidation is the process by which a metal loses electrons, resulting in an increase in its oxidation state.

Boron trifluoride is a Lewis acid because it can accept a pair of electrons to form a coordinate bond.

The compound with the formula $H_2SO_4$ is called sulfuric acid, a strong mineral acid.

Iron is a transition metal, characterized by its partially filled d orbitals.

The compound with the formula $NaCl$ is called sodium chloride, also known as common salt.

Fluorine, chlorine, bromine, and iodine are all halogens, characterized by their high reactivity and ability to form diatomic molecules.

The compound with the formula $CO_2$ is called carbon dioxide, a colorless, odorless gas.

Sodium is a main group element, also known as an alkali metal, characterized by its one valence electron.