42 terms

vocabulary general biology chapter 2

general biology chapter 2.
Any substance that cannot be broken down to any other substance by chemical reactions.
A compound resulting form the formation of an ionic bond; also, called an ionic compound.
A substance consisting of two or more different elements combined in a fixed ration.
Van Der walls interactions:
Weak attractions between molecules or parts of molecules that result from transient local partial charges.
Electron shell:
An energy level of electrons at a characteristic average distance from the nucleus of an atom
atomic nucleus
An atom's dense central core, containing protons and neutrons.
Ionic compound:
A compound resulting from the formation of an ionic bond; also called a salt
Valence shell:
The outermost energy shell of an atom, containing the valence electrons involved in the chemical reactions of that atom.
The attraction of a given atom for the electrons of a covalent bond.
Trace element:
An element indispensable for life but required in extremely minute amounts.
Nonpolar covalent bond:
A type of covalent bond in which electrons are shared equally between two atoms of similar electronegativity
Atomic mass:
The total mass of an atom, which is the mass in gram of 1 mole of the atom.
The capacity to cause change, especially to do work ( to move matter against an opposing force).
Mass number:
The sum of the number of protons and neutrons in an atom's nucleus.
Hydrogen bond:
A type of weak chemical bond that is formed when the slightly positive hydrogen atom of a polar covalent bond in one molecule is attracted to the slightly negative atom of a polar covalent bond in another molecule or in another region of the same molecule.
Single bond:
A single covalent bond; the sharing of a pair of valence electrons by two atoms.
Polar covalent bond:
A covalent bond between atoms that differ in electronegativity.
The shared electrons are pulled closer to the more electronegative atom, making it slightly negative and the other tom slightly positive.
Radioactive isotope:
An isotope ( an atomic form of a chemical element ) that is unstable; the nucleus decays spontaneously, giving off detectable particles and energy.
A subatomic particle having no electrical charge (electrically neutral), with a mass of about 1.7 7 times; 10-24g, found in the nucleus of an atom.
One of several atomic of a element, each with the same number of protons but a different number of neutrons, thus differing in atomic mass.
A subatomic particle with a single positive electrical charge, with a mass of about 1.7 & time; 10-24 g found in the nucleus of an atom.
Anything that takes up space and has mass
Chemical bond:
An attraction between two atoms, resulting from a sharing of outer-shell electrons or the presence of opposite charges on the atoms. The bonded atoms gain complete outer electron shells.
A subatomic particle with a single negative electrical charge and a mass about 1/2000 that of a neutron or proton. One or more electrons more around the nucleus of an atom.
The three-dimensional space where an electron is found 90% of the time.
Chemical reaction:
The making and breaking of chemical bonds, leading to changes in the composition of matter
A material resulting from a chemical reaction.
A starting material in a chemical reaction.
Cat ion:
A positively charged ion.
Potential energy:
The energy that matter possesses as a result of its location or spatial arrangement (structure)
A negatively charge ion.
Covalent bond:
A type of strong chemical bond in which two atoms share one or more pairs of valence electrons.
Ionic bond:
A chemical bond resulting from the attraction between oppositely charged ions.
Valence electron:
An electron in the outermost electron shell.
The smallest unit of matter that retains the properties of an element.
An atom or group of atoms that has gained or lost one or more electrons, thus acquiring a charge.
chemical equilibrium
A chemical element required for an organism to survive, grow, and reproduce.
Chemical equilibrium:
In a chemical reaction, the state in which the rate of the forward reaction equals the rate of the reverse reaction, so that the relative concentrations of the reactants and products fo not change with time.
Double bond:
A double covalent bond; the sharing of two of valence electrons by two atoms.
Atomic number:
Atomic number:
A measure of mass for atoms and subatomic particles; the same as atomic mass unit amu.
Bonding capacity of a given atom; usually equals the number of unpaired electrons required to complete the atom's outmost valence shell.