Chemistry 2nd Quarter exam review

Chemical bond

Mutual electrical attraction between the nuclei and valence electrons of different atoms that binds the atoms together.

Point of chemical bonding

The atoms want to become more stable

Ionic bonding

The chemical bond resulting from electrical attraction between large numbers of cations and anions

Cation

Positive ion

Anion

Negative ion

Covalent bond

Chemical bond resulting from the sharing of an electron pair between two atoms

Polar-Covalent bond

Covalent bond where the bonded atoms have an unequal attraction for the shared electrons

Non-Polar Covalent bond

Covalent bond where the bonding electrons are shared equally by the bonding of atoms resulting in a balanced distribution of electrons charge

Diatomic elements

H-O-N-Cl-Br-I-F, Hydrogen, Oxygen, Nitrogen, Chloride, Bromide, Iodine, Florine

Octet rule

Chemical compounds tend to form where they gain, lose or share electrons, and has an octet (set of 8) electrons in its highest occupied energy level

Lewis structures

Dot diagram that provides visual representations of valence electrons in a covalent bond between atoms of a molecule.

Shared electron pair

Electrons between atoms that have formed covalent bonds

Unshared electron pair

Electron pair not involved in chemical bonding. Also frequently referred to as a "lone pair".

Single bond

A covalent bond where two atoms share one pair of electrons

Multiple bond

A double or triple bond in a covlaent bond

Ionic compound

Compound composed of positive and negative ions that are combined so that the numbers of positive and negative charges are equal

Formula unit

The simplest collection of atoms from where an ionic compound's formula can be established

Polyatomic ion

A charged group of covalently bonded atoms

Metallic bonding

Chemical bonding that results from the attraction between metal atoms and the surrounding sea of electrons

VSEPR theory

Valence Shell Electron Pair Repulsion. Repulsion between sets of valence-level electrons surrounding an atom causing the sets to be oriented as far apart as possible

Intermolecular forces

The force of attraction between molecules

Hydrogen bonding

Intermolecular force in which a hydrogen atom that is bonded to a highly electronegative atom is attracted to an electronegative atom in a nearby element

Molar mass

Elements : check periodic table Grams/Mole

Molecules: add up masses of each element Grams/Mole

Percent composition

Total mass of element or compound present devided by the mass of each element in the compound or just the lone element

Empirical formula

Simplest or most reduced ratio of atoms in a compound

https://www.youtube.com/watch?v=wnRaBWvhYKY

Molecular formula

"Regular Formula" How many atoms of each atom are in a compound

Chemical formula

Formula that indicates the relative numbers of atoms of each kind in a chemical compound by using atomic symbols and numerical subscription

Subscript

Number that indicates the amount of a certain element

Monatomic ions

Ion formed from a single atom

Oxidation numbers

a number assigned to an atom in a molecular compound or ion that indicates the general distribution of electrons among the bonded atoms

Chemical equation

Representation with symbols and formulas of the identities and relative amounts of the reactants and products in a chemical reaction

Evidence of chemical reaction

Evolution of heat and light

Production of a gas

Formation of precipitate

Color change

Precipitate

Solid that is produces as a result of a chemical reaction in solution and that separates from the solution

Coefficient

A number in front of a chemical formula in an equation that indicates how many molecules or atoms of each reactant and product are involved in a reaction

Reason for balancing chemical equations

Satisfy the law of conservation of mass

Synthesis/Composition reaction

A+B = AB

Decomposition reaction

AB = A+B

Double replacement reaction

AX+BY = AY+BX