Term
|
Definition
| the study of carbon compounds |
|
|
Term
|
Definition
| the number of protons in the nucleus of an atom |
|
|
Term
|
Definition
| the total of protons plus neutrons |
|
|
Term
|
Definition
| atoms of the same element that have different mass numbers |
|
|
Term
|
Definition
| the average mass number of the atoms of an element |
|
|
Term
|
Definition
| a wave function, which describes the volume of space around a nucleus in which an electron is most likely found |
|
|
Term
|
Definition
| a surface of zero electron density within an orbital |
|
|
Term
| ground-state electron configuration |
|
Definition
| the most stable, lowest energy electron configuration of a molecule or atom |
|
|
Term
| electron configuration rules |
|
Definition
| 1) the lowest energy orbitals fill first, according to the order 1s->2s->2p->3s->3p->4s->3d, a statement called the aufbau principle; 2) electrons act as if they were spinning around an axis, in much the same way that the earth spins. This spin can have two orientations, denoted as up and down arrows; only two electrons can occupy an orbital, and they must be of opposite spin, a statement called the Pauli exclusion principle; 3) if two or more empty orbitals of equal energy are available, one electron occupies each with spins parallel until all orbitals are half full,a statement called Hund's rule |
|
|
Term
|
Definition
spherical shape; one per shell [image] |
|
|
Term
|
Definition
dumbell shaped; three mutually perpendicular per shell, denoted as px, py, pz [image] |
|
|
Term
|
Definition
4 of 5 are cloverleaf shaped and the fifth is an elongated dumbell shape with a donut around the middle; five per shell [image] |
|
|
Term
|
Definition
| the layers in which the orbitals of an atom are organized into; they become progressively larger and higher in energy the further from the atom they are |
|
|
Term
|
Definition
| the outermost shell of an atom |
|
|
Term
|
Definition
| a shared-electron bond between atoms |
|
|
Term
|
Definition
| the neutral collection of atoms held together by covalent bonds |
|
|
Term
|
Definition
| aka Lewis structures; a way of representing the valence electrons of an atom as dots |
|
|
Term
|
Definition
| aka Kekule structures; a two-electron covalent bond is indicated as a line drawn between atoms |
|
|
Term
| lone-pair electrons/nonbonding electrons |
|
Definition
| valence electrons that are not used for bonding |
|
|
Term
|
Definition
when two atoms approach each other closely and a singly occupied orbital on one atom overlaps a singly occupied orbital on the other atom, a covalent bond forms between the two atoms ex., H-H bond [image] |
|
|
Term
|
Definition
| a covalent bond formed by head-on overlap of atomic orbitals |
|
|
Term
|
Definition
| an alternative name for bond dissociation energy (the energy required to break a bond) |
|
|
Term
|
Definition
| the equilibrium distance between the nuclei of two atoms that are bonded to each other |
|
|
Term
|
Definition
a hybrid orbital derived by combination of an s atomic orbital with three p atomic orbitals; the four orbitals that result are directed toward the corners
of a regular tetrahedron at angles of 109° to each other; they form stronger bonds than regular s or p orbitals |
|
|
Term
|
Definition
the angle formed between two adjecent bonds; e.g., the tetrahedral orientation of methane (CH4) where each H is 109.5° from the other |
|
|
Term
|
Definition
contain 109.5° angles, e.g., methane [image] |
|
|
Term
|
Definition
120° angles between orbitals [image] |
|
|
Term
|
Definition
| a hybrid orbital derived by combination of an s atomic orbital with 2 p atomic orbitals; the three orbitals that result lie in a plane at angles of 120° to each other, and the other p orbital remains unchanged; shown as double bonds |
|
|
Term
|
Definition
| the covalent bond formed by sideways overlap of atomic orbitals; e.g., carbon-carbon double bonds |
|
|
Term
|
Definition
a hybrid orbital derived from the combination of an s and a p atomic orbital; the two orbitals that result are oriented at an angle of 180° to each other and the remaining two p orbitals are left unchanged; shown as triple bonds
|
|
|
Term
|
Definition
180° angles; e.g., acetylene [image] |
|
|
Term
| molecular orbital (MO) theory |
|
Definition
| a description of covalent bond formation as resulting from a mathematical combination of atomic orbitals (wave functions) to form molecular orbitals |
|
|
Term
|
Definition
| a molecular orbital that is lower in energy than the atomic orbitals from which it is formed |
|
|
Term
|
Definition
| a molecular orbital that is higher in energy than the atomic orbitals from which it is formed |
|
|
Term
|
Definition
| a shorthand way of writing structures in which carbon-hydrogen and carbon-carbon bonds are understood rather than shown explicitly; e.g., propane = CH3CH2CH3 |
|
|
Term
|
Definition
a shorthand way of writing structures in which carbon atoms are assumed to be at each intersection of two lines (bonds) and at the end of each line; e.g., phenol, C6H6O [image] |
|
|
Term
| rules for drawing skeletal structures |
|
Definition
| 1) carbon atoms aren't shown but are assumed to be at each intersection and at the end of lines; 2) hydrogen bonded to carbon is not shown - carbon always has a valence of 4, thus the hydrogens are known to be there; 3) atoms other than H and C are shown |
|
|
