Shared Flashcard Set

Details

Biology AP
Ch.2 The Chemical Context of Life
33
Biology
12th Grade
09/11/2007

Additional Biology Flashcards

 


 

Cards

Term
Element
Definition
substance that cannot be broken down to other substances by chemical reactions; there are 92 elements; Carbon, Oxygen, Hydrogen, and Nitrogen make up 96% of living math; Phosphorous, Sulfur, Calcium, Potassium make up remaining 4%
Term
Compound
Definition
substance consisting of 2 or more different elements combined in a fixed ratio;Ex: NACl 1:1
Term
Trace Element
Definition
required by an organism in only minute quantities; Iron is needed by all forms of life
Term
Atom
Definition
smallest unit of matter that still retains the properties of an element
Term
Neutrons, Protons, Electrons
Definition
Neutrons (no charge), Protons (+) are packed together in center of atom to form the nucleus; electrons (-) moving around the center form a cloud
Term
atomic #
Definition
# of protons and electrons in atom
Term
mass #
Definition
sum of protons plus neutrons
Term
atomic mass
Definition
the total mass of an atom, which is the mas in grams of 1 mole of the atom
Term
isotope
Definition
Forms of the same chemical element that differ only by the number of neutrons in their nucleus. Most elements have more than one naturally occurring isotope
Term
radioactive isotope
Definition
An isotope of an element that has an unstable nucleus; it tries to stabilize itself by giving off ionizing radiation
Term
energy
Definition
the capacity to caus change, for instance by doing work
Term
potential energy
Definition
the energy that matter possesses because of its location or structure; Ex: water in a reservoir on a hill has potential energy
Term
energy levels
Definition
different states of potential energy that electrons have in an atoms
Term
electron shells
Definition
average distance from the nucleus; the closer to the nucleus the lower the potential energy
Term
valence electrons
Definition
Electrons in the outermost or highest-energy orbitals of an atom; the electrons that are gained or lost in a chemical reaction.
Term
valence shell
Definition
the outermost shell of an atom, which contains the electrons most likely to account for any reactions involving the atom and of the bonding interactions it has with other atoms
Term
electron orbital
Definition
the route around the nucleus of an atom that an electron travels
Term
chemical bond
Definition
an attraction between 2 atoms by the sharing of valence electrons or the presence of opposite charges on the atom; the bonded atoms gain complete outer electron shells
Term
covalent bond
Definition
2 atoms share 1 or more pairs of valence electrons
Term
molecule
Definition
2 or more atoms held together by covalent bond
Term
single bond
Definition
a pair of shared electrons; Ex: H-H
Term
double bond
Definition
sharing of 2 electrons pairs; Ex: 0=0
Term
valence
Definition
the bonding capacity of an atom, generally = to the # of unpaired electrons in the atoms outermost shells
Term
electronegativity
Definition
the attraction of an atom for the electrons of a covalent bond
Term
non-polar covalent bond
Definition
a type of bond in which electrons are shared equally between 2 atoms of similar electro-negativity
Term
polar covalent bond
Definition
a bond between atoms that differ in electron-egativity; the shared electrons are pulled closer to the more electronegative atom, making it slightly negative and the other atom slightly +
Term
ion
Definition
a charged atom or molecule
Term
cation
Definition
when ion is specifcally +
Term
anion
Definition
a - ion
Term
ionic bond
Definition
a chemical bond resulting from the attraction between 2 oppositely charged ions; also called salts
Term
hydrogen bond
Definition
weak chemical bond formed when the slightly + hydrogen atom of a polar covalent bond in 1 molecule is attracted to the slightly - atom of a polar covalent bond in another molecule
Term
van der Waals interaction
Definition
a weak interaction between molecules or parts of molecules that are brought about by localized charge fluctuations
Term
Chemical reaction
Definition
change reactants into products while conserving matter; most are reversible; Chemical equilibrium is reached when the forward and reverse reaction rates are =
Supporting users have an ad free experience!