Untitled Flashcards Set

Why do atoms form bonds?

Atoms form bonds to achieve greater stability by filling their outer electron shells.

Electronegativity

A measure of the tendency of an atom to attract a bonding pair of electrons.

Valence electrons

Electrons in the outermost shell of an atom that determine its chemical properties.

Octet rule

Atoms tend to form bonds in such a way that they have eight electrons in their valence shell.

Exceptions to the octet rule

Certain elements can have fewer or more than eight electrons in their valence shell. (Be - 4, B-6, P-10, S-12)

Chemical bond

A lasting attraction between atoms that enables the formation of chemical compounds.

Covalent bond

A type of bond where atoms share electrons, resulting in a stable balance of attractive and repulsive forces between them. (metal + metal)

Single bond

A covalent bond in which one pair of electrons is shared between two atoms. (longest bond length and lowest bond strenght)

Double bond

A covalent bond in which two pairs of electrons are shared between two atoms.

Triple bond

A covalent bond in which three pairs of electrons are shared between two atoms. shortest bond distance and greatest bond energy.

Bond length

The distance between the nuclei of two bonded atoms.

Polar covalent bond

A type of bond where the electrons are shared unequally, leading to a dipole moment. (0.4 EN - 1.7 EN)

Nonpolar covalent bond

A type of bond where electrons are shared equally between atoms.

Molecule

A group of atoms bonded together, representing the smallest fundamental unit of a chemical compound.

Molecular formula

A representation of a molecule that shows the number and type of atoms present.

Bond energy

The amount of energy required to break one mole of bonds in gaseous molecules.

Chemical formula

The simplest ratio of an ionic compound that creates electrical neutrality.

Resonance

A phenomenon where a molecule can be represented by two or more valid Lewis structures.

Polyatomic ions

Ions that consist of two or more atoms bonded together covalently that carry a charge. Combined of ions of opposite charges.

Electron dot notation

A representation that shows valence electrons as dots around the chemical symbol of an element.

Lewis Electron Dot Diagrams

Diagrams used to depict the bonding between atoms and the lone pairs of electrons.

Ionic bond

A type of chemical bond formed through the transfer of electrons from one atom to another. (nonmetal + metal)

Ionic compound

A compound composed of ions held together by ionic bonds. nonmetal and metal. Strong electrostatic attraction between negative and positive ions.

Formula unit

The lowest whole number ratio of ions in an ionic compound.

Crystal lattice

The symmetrical three-dimensional arrangement of atoms inside a crystal.

Lattice energy

The energy released when ions bond together to form a crystal lattice.

Metallic bond

The attraction between metal atoms and the surrounding sea of electrons.

Sea of electrons

A model that describes the delocalized electrons within a metallic structure.

Metallic properties

Properties such as conductivity, malleability, and ductility resulting from metallic bonding.

Enthalpy of Vaporization

The amount of energy required to convert a metal substance from liquid to gas. (proportional to nuclear charge)

Properties of ionic compounds

Typically high melting and boiling points, conduct electricity when dissolved in water, and a strong bond

Properties of molecular compounds

Typically lower melting and boiling points compared to ionic compounds, do not conduct electricity.

Properties of metals

Good conductors of heat and electricity, malleable, ductile, and have a shiny appearance.