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43 terms

Ch. 2 Atoms and Molecules: The Chemical Basis of Life

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Molecular Biology
Chemistry and Physics of the molecules that constitute living things
Inorganic Compounds
Water, many simple acids and bases, and simple salts
Organic compounds
Carbon-containing compounds that are generally large and complex
Elements
substances that cannot be broken down into simpler substances by ordinary means
Atomic number
The fixed number of prtons that help identify an element
AMU Dalton
Equal to the mass of a single proton or neutron
Atomic mass
Number that indicates approximately how much matter an atom contains
Isotopes
Name for an element with a different number of neutrons and atomic mass
Radioisotopes
emit radiation when they decay
Autoradiography
Radiation causes the appearance of dark silver grains in photographic film
Orbitals
Contains 2 electrons max. Region of 3-d space
Electron shell
Made up of electrons at similar energy levels, AKA same principal energy level
Valence Electrons
Most energetic and outward electrons
Simplest Formula
AKA empirical. Gives smallest whole-number ratios for the atoms present in compound
Molecular Formula
Gives actual number of each type of atom per molecule
Structural Formula
Shows numbers and arrangement of molecules
Molecular Mass
Sum of the atomic masses ofthe component atoms of a single molecule
Mole
Amount of an element/compound whoese mass in grams is equivalent to its atomic mass
Avogadro's Number
6.022 * 10 23
Dynamic Equilibrium
Rates of forward and backward reactions are equal
Bond energy
Energy necessary to break a chemical bond
Covalent Bond
involves sharing of electrons between atoms
Orbital hybridization
Covalent bonds reform the molecule into a new shape
Electronegativity
Measure of an atom's attraction for shared electrons in chemical bonds
Cation
Positively charged ion
Anion
Negatively charge ion
Solvent
Liquid capable of dissolving many substances
Solute
dissolved substance
Hydration
In solution, each cation and anion of the compound is surrounded by oppositely charged ends of water molecules
Hydrogen Bond
Hydrogen becomes part of a molecule and becomes polar and attracts negative to positive
Van der waals interactions
Adjacent molecules may interact in regions of slight opposite charge
Redox Reaction
An electron transfer that involves the transfer of the energy, oxidation-reduction
Oxidation
Chemical process when atom, ion or molecule loses electrons
Reduction
Chemical process in which an atom, ion or molecule gains electrons
Cohesion
Name for the ability of water to stick to itself, causes surface tension
Adhesion
Name for the ability of water to stick to other surfaces
Capillary action
Tendency of water to move in narrow tubes
Hydrophilic
Water loving
Hydrophobic
Water fearing
Heat of vaporization
Amount of heat energy required to change 1 g of a substance from liquid to vapor
Calorie
amount of heat energy required to raise the temp of 1 g of water 1 degree C
Evaporative cooling
When molecules escape and take their heat energy with them, cooling the sample
Specific Heat
Amount of energy required to raise the temperature of a substance