Chapter 2 - The Chemical Context of Life

	anything that takes up space and has mass
	a substance that cannot be broken down to other substances by chemical reactions
	a substance consisting of two or more different elements combined in a fixed ratio
	an element indispensable for life but required in extremely minute amounts
	the smallest unit of matter that still retains the properties of an element
	particles inside an atom (protons, neutrons, electrons)
	a subatomic particle having no electrical charge (electrically neutral) with a mass of about 1.7 * 10^-24 g, found in the nucleus of the atom
	a subatomic particle with a single positive electrical charge, with a mass of about 1.7 * 10^-24 g, found in the nucleus of the atom
	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 move around the nucleus of an atom
	an atom's dense central core, containing protons and neutrons
	a measure of mass for atoms and subatomic particles; the same as the atomic mass unit or amu
	the number in the nucleus of an atom, unique for each element and designated by a subscript to the left of the elemental symbol
	the sum of protons plus neutrons in the nucleus of an atom
	the total mass of an atom, which is the mass in grams of 1 mole of the atom
	one of several atomic forms of an element, each with the same number of protons but a different number of neutrons, thus differing in atomic mass
	an isotope in which the nucleus decays spontaneously, giving off particles and energy
	the capacity to cause change
	the energy that matter possesses because of its location or structure
	an energy level of electrons at a characteristic average distance from the nucleus of an atom
	an electron in the outermost electron shell
	the outermost energy shell of an atom, containing the valence electrons involved in the chemical reactions of that atom
	the three dimensional space where an electron is found 90% of the time
	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
	the sharing of a pair of valence electrons by two atoms
	two or more atoms held together by covalent bonds
	a single covalent bond; the sharing of a pair of valence electrons by two atoms
	a type of of molecular notation in which the constituent atoms are joined by lines representing covalent bonds
	a type of molecular notation representing the quantity of constituent atoms, but not the nature of the bonds that join them
	a double covalent bond; the sharing of two pairs of valence electrons by two atoms
	the bonding capacity of a given atom; usually equals the number of unpaired electrons required to complete the atom's outer most (valence) shell
	the attraction of a given atom for the electrons of a covalent bond
	a type of covalent bond in which electrons are shared equally between two atoms of similar electronegativity
	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 atom slightly positive.
	a charged atom or molecule
	an ion with a positive charge
	a negatively charged ion
	a chemical bond resulting from the attraction between oppositely charged ions
	a compound resulting from the formation of an ionic bond, also called a salt
	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
	weak attractions between molecules or parts of molecules that result from localized charge fluctuations
	the making and breaking of chemical bonds, leading to changes in the composition of matter
	a starting material in a chemical reaction
	a material resulting from a chemical reaction
	the point at which reactions offset one another exactly