Chapter 6 Chemistry Complete And Verified

Chapter 6 Chemistry Complete And Verified Chemical Bonds Chemical bonds are formed through the mutual electrical attraction between the nuclei and valence electrons of different atoms. This attraction binds the atoms together, forming a chemical bond. Types of Chemical Bonds Ionic bonding occurs when there is an electrical attraction between large numbers of cations and anions. Covalent bonding, on the other hand, results from the sharing of electron pairs between two atoms. Polarity of Covalent Bonds Nonpolar covalent bonds occur when the bonded atoms share electrons equally, resulting in a balanced distribution of electrical charge. Polar covalent bonds, however, have an uneven distribution of charge, leading to a partial positive or negative charge on each atom. Molecules and Molecular Compounds A molecule is a neutral group of atoms held together by covalent bonds. Molecular compounds are chemical compounds whose simplest units are molecules. Chemical Formulas Chemical formulas use atomic symbols with numerical subscripts to convey the relative proportions of atoms in a substance. Molecular formulas show the types and numbers of atoms combined in a single molecule. Bond Characteristics Bond length refers to the distance between two bonded atoms at their minimum potential energy. Bond energy is the energy required to break a chemical bond and form neutral isolated atoms. Octet Rule The octet rule states that chemical compounds tend to form so that each atom gains, loses, or shares electrons to achieve an octet of electrons in its highest occupied energy level. Electron Notation Electron-dot notation is a way to represent the valence electrons of an atom using dots placed around the element's symbol. Lewis structures are formulas that use this notation to show electron pairs in covalent bonds and unshared electrons. Structural Formulas Structural formulas indicate the kind, number, arrangement, and bonds between atoms in a molecule, but do not show unshared pairs. Multiple Bonds Single bonds involve the sharing of a pair of valence electrons between two atoms. Double bonds involve the sharing of two pairs of electrons, while triple bonds involve the sharing of three pairs. Resonance Resonance occurs when bonding molecules or ions cannot be correctly represented by a single Lewis structure, indicating that multiple structures contribute to the overall bonding arrangement. ionic compound ️Composed of positive and negative ions that are combined so that the numbers of positive and negative charges are equal formula unit ️the simplest collection of atoms from which an ionic compound's formula can be established lattice energy ️the energy released when one molecule of an ionic crystalline compound is formed from gaseous ions polyatomic ion ️A charged group of covalently bonded atoms metallic bonding ️the chemical bonding that results from the attraction between metal atoms and the surrounding sea of electrons malleability ️the ability of a substance to be hammered or beaten into thin sheets ductility ️the ability of a substance to be drawn, pulled, or extruded through a small opening to produce a wire molecular polarity ️the uneven distribution of molecular charge VSEPR theory ️states that repulsion between the sets of valence-level electrons surrounding an atom causes these sets to be oriented as far apart as possible hybridization ️the mixing of two or more atomic orbitals of similar energies on the same atom to produce new orbitals of equal energies intermolecular forces ️forces of attraction between molecules dipole ️created by equal but opposite charges that are separated by a short distance