Matter
Anything that contains mass and occupies space
Atoms
Smallest units of matter that form all chemical substances (all organisms)
Molecules
2 or more atoms bonded together
element
A pure substance of only one kind of atom
Protons
Positive (nucleus)
Neutrons
Neutral (nucleus)
Electrons
Negative
Atomic nucleus
Small volume in the center of the atom
Orbitals
Region of space surrounding the nucleus (electrons)
Electron shells
Energy levels
Energy
Capacity to do work or effect a change
Valence electrons
Electrons in the outer most shell
Atomic number
Number of protons in an atom
Atomic mass
Atoms mass relative to other atoms
Dalton (Da)
Atomic mass unit
Isotopes
Elements that differ in their number of neutrons
Radioisotopes
An unstable isotope that usually does not exist for long periods of time (decay and emit radiation)
Trace elements
Essential for normal function in living organisms but in extremely small qualities
Molecular formula
Chemical symbols and subscripts
Compound
A molecule composed of two or more different elements
Covalent bonds
Two atoms SHARE a pair of electrons
Octet rule
States most atoms are most stable when their outer shell is full with eight electrons
Double bond
Atoms of a molecule share two pairs of electrons
Electro negativity
Measure of an atoms ability to attract electrons to it's outer she'll from another atom
Polar covalent bonds
Distribution of of electrons create Different electro negativities across a molecule.
Non polar covalent bonds
Strong bond with similar electro negativity.
Nonpolar molecules
Molecule composed of predominantly non polar bonds
Hydrogen bond
Weak chemical attraction between partially + hydrogen and a polar molecule and a partially - polar atom
Enzymes
Protein that acts as a catalyst to speed up a chemical reaction
Van der waals forces
Attractive forces b/w molecules in close proximity to each other, cause by the variations in the distribution of electron density around individual atoms.
Ion
Atom or molecule that gains or loses one or more electrons and acquires a net electric charge
Cation
A ion that has a net positive charge
Anion
An ion that has a net negative charge
Ionic bond
The bond that occurs when a cation binds to an anion
Free radicals
Can react with other molecules to steal an electron from one of their atoms (unstable)
Chemical reaction
The formation and breaking of chemical bonds resulting in a change in the composition of substances
Catalyst
Substance that speeds up a chemical reaction
Reactants
Participates in a chemical reaction and is changed by the reaction
Products
The end result of a chemical reaction
Chemical equilibrium
Rate of formation of products equals the rate of formation of reactants
Solutes
Substances dissolves in a liquid
Solvent
Liquid in which they are dissolved
Solution
Solutes dissolve in solvents to form a...
Aquenous solutions
A solution made with water
Hydrophilic
Refers to ions and molecules that contain polar covalent bonds and will dissolve in water
Hydrophobic
Refers to molecules that do not have partial charges and therefore are not attracted to water
Amphipathic
Molecules containing a hydrophobic region and a hydrophilic region
Micelle
The sphere formed by long Amphipathic molecules when they are mixed with water
Concentration
The amount of solute dissolved in a unit volume of solution
Molecular mass
The sum of the atomic masses of all the atoms in a molecule
Molarity
The number of moles of a solute dissolved in 1 L of water
Molar
Describes a solutions Molarity
Hear of vaporization
The heat required to vaporize 1 mile of any substance at it's boiling point
Heat of fusion
The amount of heat energy that must be withdrawn or released from a substance to cause it to change from a liquid to solid
Specific heat
The amount of energy required to raise the temp of 1 gram of a substance by 18degrees C
Colligative properties
Property of a solution that depends only on the concentration of solute molecules
Hydrolysis reaction
A chemical reaction that utilizes water to break apart molecules
Condensation reaction
A chemical reaction in which two or more molecules are combined into one larger molecule by covalent bonding, with the loss of a small molecule
Dehydration
A type of condensation reaction in which a molecule of water is lost
Evaporation
The transformation of water from liquid to gas
Cohesion
The ability of like molecules to noncovalently bind to each other. Attraction of water molecules to each ither
Adhesion
Ability of two different substance to bind to each other
Surface tension
Measure of how difficult it is to break the interface between liquid and air
Hydroxide ion
An anion with formula OH-
Acids
Substances that release hydrogen ions in a solution
Strong acid
Completely ionizes in solution
Weak acid
Only partially ionizes in a solution
Base
1. When dissolved in water lowers H+ concentration
2. Component of nucleotides that is a single or double ring of carbon and nitrogen atoms
Acidic
A solution that had a ph below 7
Alkaline
A solution with a ph above 7
Buffer
A compound that acts to minimize oh fluctuations in the fluids of living organisms