[L1] 1 Ionic Bond [L2] 1) Definition [L4] - A bond based on electrostatic attraction between charged cations and anions. [L5] * Elements with a high tendency to become cations: Alkali metals, Alkaline earth metals. [L5] * Elements with a high tendency to become anions: Halogens, Oxygen. [L5] * However, the tendency to become cations or anions is relative. [c] [c] Source: Naver Encyclopedia [L2] 2) Features [L4] - Most substances correspond to ionic bonds. [L4] - Compounds of ionic bonds have high melting points. [L5] * Occurs due to high lattice energy. [L4] - Although composed of cations and anions, solid-state ionic compounds are electrically neutral. [L4] - Electrical resistance is high (Insulator). [L5] * Because ions cannot easily move from lattice positions. [L5] * When dissolved in water, etc., cations and anions move freely in the solution, becoming an electrolyte solution with high conductivity. [L2] 3) Types [L4] - Combinations of strongly positive metals and strongly negative non-metals are common. [L5] * Sodium Chloride, Aluminum Oxide (Sapphire), Silicon Oxide (Glass). [L1] 2 Covalent Bond [L2] 1) Definition [L4] - A strong chemical bond formed as atoms share electron pairs, filling the outermost electron orbit of the atom to form a stable electron structure. [L4] - One of the chemical bonds, formed by two atoms releasing electrons to each other to form an electron pair and sharing it. [L4] - Also called electron pair bond or homopolar bond. [c] [c] Source: Naver Encyclopedia [L2] 2) Features [L4] - Substances made of covalent bonds are generally classified as molecules. [L4] - A bond created by balancing attraction and repulsion between atoms. [L4] - Triple bonds are stronger than double bonds, and double bonds are stronger than single bonds. [L2] 3) Types [L4] - Covalent bonds are mainly formed between non-metal elements with small differences in electronegativity. [L4] - Almost all organic compounds and some inorganic compounds are composed of covalent bonds. [L4] - Hydrogen Molecule: Hydrogen has one electron in the 1s orbital. By sharing its electron with another hydrogen atom, each hydrogen atom fills the 1s orbital completely with two electrons, having a stable electron structure (Molecularization). [L1] 3 Metallic Bond [L2] 1) Definition [L4] - Metal atoms bonding through free electrons. [L4] - When electrically neutral atoms form a solid crystal to form a metal, the outermost electrons located in the lattice escape to become cations, and the escaped electrons form conduction electrons. The bond resulting from the electrostatic attraction between these formed cations and conduction electrons is called a metallic bond. [c] [c] Source: Naver Encyclopedia [L2] 2) Features [L4] - Conduction electrons in metal can move freely everywhere within the solid. [L5] * Has high electrical conductivity and thermal conductivity. [L4] - The force acting between cations and conduction electrons is an electrostatic force, having a very strong bond. [L5] * Very large energy is required for the phase change of metallic bond materials. In other words, melting and boiling points are high. [L5] * Has properties of ductility and malleability. In other words, a phenomenon where the lattice positions of cations change.