Mod 1 Chemistry

Electronegativity

A measure of an element's ability to attract/pull electrons when sharing with another element.

Pauling Scale

A scale used to quantify electronegativity values of elements.

Non-polar covalent bond

A bond with a difference in electronegativity of 0, where electrons are equally shared (e.g., Cl₂, N₂).

Polar covalent bond

A bond with a difference in electronegativity greater than 0 but less than 1.7, where electrons are unequally shared (e.g., H-Cl, H-O).

Ionic bond

A bond with a difference in electronegativity greater than 1.7, where electrons are transferred (e.g., NaCl, ZnO).

Nomenclature in ionic bonding

Compounds end in -ide, cation is named first, and Roman numerals indicate oxidation state for transition metals.

Nomenclature in covalent bonding

Prefixes indicate the number of atoms, with the more electronegative element named last.

Chemical formula in ionic bonding

Represents a simplified ratio of ions, with Lewis structures showing ions in brackets with assigned charges.

Chemical formula in covalent bonding

Subscripts indicate the number of atoms, and Lewis structures must satisfy the octet rule.

Valency

Metals form positive ions, non-metals form negative ions; ionic compounds involve electron transfer, while covalent compounds involve electron sharing.

Molecular shapes

Only covalent compounds form molecules, with shapes including linear, bent, trigonal planar, pyramidal, and tetrahedral.

Allotropes

Different physical forms of the same element with the same chemical properties but different physical traits (e.g., carbon, oxygen, phosphorus).

Ionic networks

Consist of positive and negative ions in a lattice structure, conducting electricity when liquid or dissolved.

Covalent networks

Atoms share electrons in a 3D lattice, resulting in high melting/boiling points and poor conductivity.

Intermolecular forces

Include dispersion forces (weakest), dipole-dipole forces (between polar molecules), and hydrogen bonding (strongest).

Intramolecular forces

Include ionic, covalent, and metallic bonding, influencing the chemical properties of substances.

Relative atomic mass

The average mass of atoms in a naturally occurring element relative to carbon-12.

Emission spectra

A series of bright lines produced by gases when heated, indicating energy transitions of electrons.

Types of radiation

Alpha (high ionizing, low penetration), beta (medium ionizing, medium penetration), and gamma (low ionizing, high penetration).

Homogeneous mixtures

Uniform mixtures that can be separated by techniques like evaporation and distillation.

Heterogeneous mixtures

Non-uniform mixtures that can be separated by techniques like magnetism and filtration.

IUPAC naming conventions

Rules for naming inorganic substances based on the type of elements involved (e.g., Type 1, Type 2, Type 3).

Atomic radii trend

Increases down a group due to added electron shells and decreases across a period due to increased nuclear charge.

Ionization energy

The energy required to remove an electron from an atom, influenced by nuclear charge and electron shielding.

Reactivity with water

Group I metals react vigorously with water, while Group II metals react less vigorously, with exceptions like magnesium.