Unit 2 Vocab: Compound Structure And Properties Flashcards
Electronegativity
The tendency for an atom of a given chemical element to attract shared electrons when forming chemical bonds
Bond polarity
the distribution of electric charge across a chemical bond between two atoms.
Two types: polar and nonpolar
Non-Polar
the charge is evenly distributed across the lonic bond
Polar
the charge is unevenly distributed across the bond. The more electronegative atom will have a partial negative charge and the other will have a partial positive
charge.
Ionic bond
Type of bond formed from the electrostatic attraction between oppositely charged ions (metal and non-metal).
Covalent bond
Type of bond that results from the sharing of an electron pair between atoms (two non-metals).
Ex: (H₂O)
Metallic Bond
arises from the electrostatic attractive force between conduction electrons and positively charged metal ions. Compound from two metals
Potential energy curve
Illustrates the forces between two atoms as a function of distance in covalent bonding.
Crystal lattice
structural arrangement of atoms or ions inside an ionic solid.
Conductors
materials or substances which allow electricity to flow through them
Ductile
the ability of a material to be stretched, pulled, or drawn into a thin wire or thread without breaking.
Malleable
ability for a metal or metal alloy to be formed into a variety of shapes.
Alloys
substance formed from the combination of two or more metals.
Interstitial Alloy
Formed between atoms with different sized radii; the smaller atoms fill the spaces between the larger atoms.
Substitutional Alloy
Formed between atoms with similar radii; one atom substitutes another in the lattice
Lewis’s structure
Diagrams that show the bonding between atoms of a molecule, as well as the lone pairs of electrons that may exist in the molecule.
Lone pairs
A pair of valence electrons that are not shared with another atom in a covalent bond and is sometimes called an unshared pair or non-bonding pair.
Diatomic elements
An element that is never found by itself in nature BrINClHOF (H, N, F, O, I, Cl, Br)
Octet rule
The tendency of atoms to prefer to have eight electrons in the valence shell
Formal charge
the difference between the number of valence electrons of an atom in a neutral free state and the number assigned to the atom.
○ FC=V-N-B/2 where
[o] FC=Formal Charge V=# of valence electrons N=Non-Bonding valence electrons and B=# of electrons shared in bonds
Resonance structure
A set of two or more Lewis Structures that collectively describe the electronic bonding of a single polytomic species. The actual structure of the polyatomic ion is a combination of the resonance structures.
VSEPR (Valence Shell Electron Pair Repulsion Theory)
A model used in chemistry to predict the geometry of individual molecules from the number of electron pairs surrounding their central atoms.
○ Negative electron domains (bond and lone pairs) repel each other
○ Electron domains will arrange themselves as far apart as possible to minimize repulsion’s
○ Electron domains count equally- lone pairs/ single/ double/triple bonds are all equivalent
○ The geometry of molecules depends on the number of electron domains
Hybridization
Happens when atomic orbitals to form new hybrid orbitals suitable for the pairing of electrons to form chemical bonds.
○ sp hybridization: 2 electron domains
○ sp² hybridization: 3 electron domains
○ sp³ hybridization: 4 electron domains
Sigma bond
A bond formed by the overlap of orbitals in an end-to-end fashin with the electron density concentrated between the nuclei of the bonding atoms.
Pi bond
A bond formed by the overlap of orbitals in a side-to-side fashin with the electron density concentrated above and below the plane of the nuclei of the bonding atoms.
○ single bond: one sigma bond
○ double bond: one sigma bond, one pi bond
○ triple bond: one sigma bond, two pi bonds
