Ionic, Covalent, and Metallic Substances: Properties Compared
Classified in Chemistry
Written at on 
English with a size of 2.54 KB.
Properties of Ionic, Covalent, and Metallic Substances
Ionic Substances
Thermal Stability: Ionic compounds are typically solid at room temperature and pressure due to strong electrostatic attractions between ions, resulting in high melting and boiling points. The greater the charge of the ions and the smaller the distance between them, the higher the melting and boiling points.
Solubility: Polar solvents can reduce the attractive forces between ions by interposing solvent molecules. Each ion becomes surrounded by solvent molecules (solvation). Solubility decreases with increasing charge of the ions. Therefore, substances containing Group IIA metals (alkaline earth metals) are generally less soluble than those formed by Group IA metals (alkali metals).
Conductivity: In solid ionic compounds, electrons are localized, and ions lack mobility. However, when melted or dissolved in aqueous solutions, the ions become mobile, allowing the substance to conduct electric current and heat.
Covalent Substances
State of Aggregation: Covalent compounds can exist in solid, liquid, or gaseous states at room temperature and pressure due to varying intermolecular attractions.
Melting and Boiling Points: Covalent compounds generally have low melting and boiling points, depending on the type of intermolecular forces present.
Conductivity: Covalent compounds are generally poor conductors of electricity and heat because they lack free charged particles in solid, liquid, or solution states.
Metallic Substances
Electrical Conductivity: Metals conduct electricity easily in solid and molten states because electrons can move freely under the influence of an electric potential.
Thermal Conductivity: The motion of particles, generated by collisions, increases with temperature, influencing the kinetic energy of particles. This increases the speed of electrons and, therefore, the transmission of heat energy.
Brightness: When light strikes a metal surface, it causes electrons to vibrate, generating electromagnetic waves with the same frequency as the incident light, resulting in the characteristic metallic luster.
Solubility: Metals are generally insoluble in water or other non-polar solvents. However, they can be soluble in other metals, forming alloys or solid solutions. Some metals, such as sodium, react violently with water.