QCM : Fundamentals of Chemical Bonding — 9 questions

Explication

Ionic bonding primarily involves the electrostatic attraction between oppositely charged ions, which are formed when electrons are transferred from a metal atom to a nonmetal atom. This process results in the formation of cations and anions that are held together in an ionic compound.

Explication

Ionic bonds form mainly through electrostatic attraction between oppositely charged ions, which results from electrons transferred from metal to nonmetal. The other options describe covalent bonding or intermolecular forces, not ionic bonding.

Explication

Water (H₂O) is a covalent compound because it is formed by sharing electrons between hydrogen and oxygen atoms, which are nonmetals. Sodium chloride (NaCl) and magnesium oxide (MgO) are ionic compounds formed by electron transfer between metals and nonmetals. Iron (Fe) is a metallic element, not a covalent compound. Therefore, water is the correct example of a covalent compound.

Explication

Sodium tends to lose electrons to form Na⁺, making it a cation. Chlorine, oxygen, and nitrogen typically form anions or share electrons in covalent bonds.

Explication

The primary role of metallic bonding is to allow metals to conduct electricity and heat efficiently, which is due to the delocalized electrons that move freely throughout the metal lattice. This property is fundamental to many uses of metals in electrical wiring, cooking utensils, and heat exchangers.

Explication

The crystalline lattice in ionic compounds accounts for their high melting and boiling points, as breaking the organized ion arrangement requires significant energy. The lattice also facilitates electricity conduction in molten or aqueous states.

Explication

Covalent bonds involve the sharing of electron pairs between atoms, unlike ionic bonds which involve electron transfer, and metallic and hydrogen bonds which have different bonding mechanisms.

Explication

An electronegativity difference greater than 1.7 usually indicates ionic bonding, as it reflects significant electron transfer, whereas smaller differences suggest covalent bonding.

Explication

Sodium chloride (NaCl) is a classic example of an ionic compound, formed by sodium and chloride ions. Methane, carbon dioxide, and water involve covalent bonds.