Chem Ch 3 Flashcards
Chemical bonds
Formed because of the attractions between charged particles. Ionic or covalent.
Ionic bonds
Between metals and nonmetals. Involved the transfer of electrons from one atom (metal) to another (nonmetal).
Covalent bonds
Between 2 or more nonmetals. Involve sharing of electrons between two atoms. Shared electrons have a lower potential energy than they would in the isolated atoms because they interact with the nuclei of both atoms.
Ionic compound
Result of ionic bond. Is composed of a lattice of alternating cations and anions in solid phase.
Lattice
A regular 3-dimensional array
Molecular compound
Covalently bonded compund. Each molecule is an independent entity (not covalently bound to other molecules. Nonmetal with nonmetal.
Chemical formula
Indicates which elements are present in the compound and the relative number of atoms or ions of each. H2O. Lists most metallic first.
3 types of chemical formulas
Empirical, molecular, structural
Empirical formula
Relative number of atoms of each element in a compound. HO.
Molecular formula
Actual number of atoms of each element in a compound. H2O2. Always a whole number multiple of the empirical formula.
Structural formula.
Uses lines to represent covalent bonds.
H2O2: H-O-O-H
CO2: O=C=O
Molecular model
More accurate and complete way to specify a compound. Ball and stick or space filling.
Atomic elements
Exist in nature with single atoms as their base units. Most elements.
Molecular elements
Exist as molecules. Most are diatomic, few polyatomic.
Diatomic elements
Oxygen, Hydrogen, Nitrogen, Fluorine, Chlorine, Bromine, Iodide.
Polyatomic elements
Phosphorous, Sulfur, Selenium.
Basic unit of molecular compounds
Molecules composed of constituent atoms
Basic unit of ionic compounds
Formula unit - smallest electrically neutral collection of ions (ie: NaCl in sodium chloride. 1:1 ratio. No single Na pairs with Cl)
Polyatomic ion
Has a charge. Covalently bonded atoms. Found in ionic compounds.
Oxyanions
Anions containing oxygen and another element.