chapter 2 Flashcards
Kinetic energy
energy in action
Potential energy
stored energy
Chemical energy
Energy stored in the bonds of chemical substances.
Electrical energy
movements of charged particles like ions
Mechanical energy
energy directly involved in moving matter.
Electromagnetic radiation
energy that travels in waves. Radio waves, infrared, visible light…
Energy
normally energy types are easily converted. energy conversions are also inefficient, energy is lost in heat.
Carbon, oxygen, hydrogen, nitrogen
make up about 96 percent of body weight.
Mass number
sum of masses of protons and neutrons.
Atoms
Protons and Neutrons are 1 amu each. Electrons are typically 0 amu. Number of protons always equal to number of electrons.
Isotopes
same number of protons and electrons, but differing numbers of neutrons. This gives the variance.
Atomic weight
average of the weights of all the isotopes of an element, taking in account of abundance in nature. Atomic weight is roughly equal to the mass number of the most abundant isotope.
Radioisotopes
Radioactive isotopes. Half life is the time required for the radioiso to lose half its activity.
Molecule
two or more chemically bonded atoms.
Compound
Molecules of different types of atoms bonded. They are chemically pure, all molecules are identical.
Mixture
substances composed of two or more components phsically intermixed.
Solutions
homogenous mixtures of components that can be gases liquids of solids. Solutes of solutions are very small.
Colloids
Heterogeneous mixture, larger sollutes than solutions. gelatins are example. sol gel transformations.
Suspensions
Heterogeneous mixture with very large solutes. ex blood.
Diff between compound and mixture
components in mixture only physicall mix, not chemically bonded.
Ionic bond
Intermediate strength. attraction between two oppositely charged ions.
Covalent bond
Very strong. Sharing electrons. slightly positive and negative ends, balanced charge overall.
Electronegativity
Electron hungry, typically round 7 electron in valence
Electropositive
round 2 electron in valence, usually ready to give up electrons
Hydrogen bond
More like attraction. intramolecular bonds that hold different parts of molecules together.
Synthesis
atoms or molecules combine to form larger complex molecules. Always bond formation. Anabolic
Decomposition
breaking down of molecule. Catabolic.
Exchange reaction
Both synthesis and decomposition. a changing of partners.
Redox reaction
Reactant losing electron the electron donor is said to be oxidized. the reactant taking up the transferred elctrons is said to become reduced.
Exergonic reaction
reactants yield products with less energy.
Endergonic reaction
Organic compounds
covalently bonded molecules. contain carbon and are made by living things.
Inorganic compounds
water, salts, acids, bases, typically dont have carbon.
Water
high heat capacity.
biological molecules dont react unless in solution. water known as the universal solvent.
Electrolyte
substance conducting electrical current in solution
Salts
Ionic compounds. ex NaCl, CaCO3, KCl
Acid
substance that releases hydrogen ions. proton donor. H is written first often in acids notations
Bases
Proton acceptors or hydrogen ion acceptors. bases have higher hydroxyl concentration
