Moles, Mass & Composition
The essential concept that provides the quantitative connection between the masses of substances reacting and the actual number of particles undergoing chemical changes
What is the mole concept?
The principle, associated with quantum mechanics, used to represent the ground-state electron configuration of an atom
What is the Aufbau principle?
This phenomenon must be included as a refinement when constructing a Lewis structure for which more than one equivalent diagram is possible
What is resonance?
A strong type of intermolecular interaction that exists between hydrogen atoms covalently bonded to N, O, or F atoms and the negative end of a dipole in a different molecule
What is hydrogen bonding?
The equation that relates the macroscopic properties of ideal gases: PV=nRT
What is the ideal gas law (PV=nRT)?
The law that states the ratio of the masses of the constituent elements in any pure sample of a given compound is always the same
What is the law of definite proportions?
The outer electrons that interact with the nuclei of other elements, determining the likelihood that two elements will form a chemical bond
What are valence electrons?
The type of bond formed between atoms of unequal electronegativity, where the atom with the higher electronegativity develops a partial negative charge
What is a polar covalent bond?
The phase of matter where particles are in constant motion and have neither a definite volume nor a definite shape
What is the gas phase?
The molecular quantity that is proportional to the Kelvin temperature of a sample of matter
What is the average kinetic energy (of the particles)?
This graphical representation of a single element is used to determine the identity of the element's isotopes and their relative abundance
What is a mass spectrum (or mass spectrometry)?
This type of spectroscopy measures the energies of electrons in a given shell, with the position of each peak related to the energy required to remove an electron from the corresponding subshell
What is Photoelectron Spectroscopy (PES)?
The VSEPR-predicted bond angle for a central atom that is sp2 hybridized
What is 120°?
The phenomenon where dispersion forces increase due to an increasing number of electrons in the molecule and the size of the electron cloud
What is polarizability?
The inverse relationship between pressure and volume of an ideal gas, provided the temperature and the number of moles remain constant.
What is Boyle's Law (or the relationship derived from PV=nRT)?
The chemical formula that lists the lowest whole number ratio of atoms of the elements in a compound
What is the empirical formula?
The mathematical law that describes the force between two charged particles, used qualitatively to understand trends like ionization energy and atomic radii
What is Coulomb’s law?
This structural model represents metallic bonding as an array of positive metal ions surrounded by delocalized valence electrons
What is the sea of electrons model (or delocalized valence electrons)?
The graphical representation, used in Kinetic Molecular Theory (KMT), that describes the distribution of kinetic energies of particles at a given temperature
What is the Maxwell-Boltzmann distribution?
In a sample containing a mixture of ideal gases, this pressure component is proportional to its mole fraction (XA) and contributes to the total pressure (Ptotal)
What is the partial pressure?
The method required to calculate quantities of a substance or its relative number of particles using the mole concept
What is dimensional analysis?
The general name for the properties of elements, such as ionization energy and atomic radii, which repeat based on the element's position on the periodic table
What is periodicity (or periodic trends)?
The distance between atoms at which the potential energy is lowest on a graph of potential energy versus internuclear distance
What is the equilibrium bond length?
The type of solid characterized by low vapor pressures, high melting points, and brittleness due to strong interactions between a systematic, periodic 3-D array of cations and anions
What are ionic solids?
The specific numerical value, 6.022×1023mol−1, that provides the constant connection between the number of moles and the number of constituent particles of a substance.
What is Avogadro's number (NA)?