Chapter 2 Flashcards
A substance that increases a hydrogen ion concentration of a solution
Acid
The clinging of one substance to another, such as water to a plant cell walls, by means of hydrogen bonds
Adhesion
A negatively charged ion
Anion
A solution in which water is the solvent
Aqueous solution
The smallest unit of matter that retains the properties of an element
Atom
The total mass of an atom, numerically equivalent to the mass in grams of one mole of the atom (For an element with more than one isotope, the atomic mass is the average mass of a naturally occurring isotopes, weighted by their abundance

Atomic mass
An atom’s dense central core, containing protons and neutrons
Atomic nucleus
A substance that reduces a hydrogen ion concentration of a solution
Base
A solution that contains a weak acid and its corresponding base. A buffer minimizes changes in pH when acids or bases are added to the solution
Buffer
Amount of heat energy required to raise a temperature of 1 g of water by 1°C; Also the amount of heat energy that 1 g of water releases when it cools by 1°C. The Callorie usually used to indicate the energy content of food is a kilo calorie
Calorie
A positively charged ion
Cation
An attraction between two atoms, resulting from a sharing of outershell electrons or the presence of opposite charges on the atoms. The bonded atoms gain complete outer electron shells
Chemical bond
The making and breaking of chemical bonds, leading to changes in the composition of matter
Chemical reaction
The linking together of like molecules, often by hydrogen bonds
Cohesion
A substance consisting of two or more different elements combined in a fixed ratio
Compound
A type of strong chemical bond in which two atoms share one or more pairs of valence electrons
Covalent bond
A measure of mass for atoms in subatomic particles; the same as the atomic mass unit or amu
Dalton
A double covalent bond; the sharing of two pairs of valence electrons by two atoms
Double bond
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
Electron
An energy level of electrons at a characteristic average distance from the nucleus of an atom
Electron shell
The attraction of a given atom for the electrons of a covalent bond
Electronegativity
Any substance that cannot be broken down to any other substances by chemical reactions
Element
The capacity to cause change especially to do work (To move matter against an opposing force)
Energy
A chemical element required for an organism to survive, grow, and reproduce
Essential element
The process in which the surface of an object becomes cooler during evaporation, a result of the molecules with the greatest kinetic energy changing from a liquid to the gaseous state
Evaporative cooling
Thermal energy and transfer from one body of matter to another
Heat
The quantity of heat a liquid must absorb for 1 g of it to be converted from a liquid to the gaseous state
Heat of vaporization
The sphere of water molecules around a dissolved ion
Hydration shell
A type of week chemical bond that is formed when the slightly positive hydrogen atom of a polar covalent bond in one molecule is attracted to a slightly negative atom of a polar covalent bond in another molecule or in another region of the same molecule
Hydrogen bond
A single proton with a charge of 1+. The dissociation of a water molecule(H2O) leads to the generation of a hydroxide ion (OH-) and a hydrogen ion (H+) ; in water, H+ is not found alone but associates with a water molecule to form a hydronium ion
Hydrogen ion
Having an affinity for water
Hydrophilic
Having no affinity for water; tending to coalesce and form droplets in water
Hydrophobic
A water molecule that has lost a proton; OH-
Hydroxide ion
An atom or group of atoms that has gained or lost one or more electrons, thus acquiring a charge
Ion
A chemical bond resulting from the attraction between oppositely charged ions
Ionic bond
A compound resulting from the formation of an ionic bond; also called a salt
Ionic compound
One of several atomic forms of an element, each with the same number of protons but different number of neutrons, does differing in atomic mass
Isotope
A unit of energy: 1 J= 0.239 Cal; one cal= 4.184 J
Joule (J)
1000 cal; the amount of heat energy required to raise the temperature of 1 kg of water by 1°C
Kilocalorie(kcal)
The energy associated with the relative motion of objects. Moving matter can perform work by imparting motion to other matter
Kinetic energy
The total number of protons and neutrons in an atom’s nucleus
Mass number
Anything that takes up space and has
Matter
A common measure of solute concentration, referring to the number of moles of solute per liter of solution
Molarity
The number of grams of a substance that equals its molecular weight and daltons and it contains Avogadro’s number of molecules
Mole (mol)
The sum of the masses of all the atoms in a molecule; sometimes called molecular weight
Molecular mass
Two or more atoms held together by covalent bonds
Molecule
A subatomic particle having no electric (e charge (electrically neutral), with a mass of about 1.7×10-24 g ,found in the nucleus of an atom
Neutron
A type of covalent bond in which electrons are shared equally between two atoms of similar electronegativity
Nonpolar covalent bond
The process by which the pH of the ocean has lowered (made more acidic) when excess CO2 dissolves in seawater and forms carbonic acid (H2CO3)
Ocean acidification
A measure of hydrogen ion concentration equal to log [H+] and ranging in value from 0 to 14
pH
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
Polar covalent bond
A molecule (such as water) with an uneven distribution of charges in different regions of the molecule
Polar molecule
The energy that matter possesses as a result of its location or spatial arrangement (structure)
Potential energy
Immaterial resulting from a chemical reaction
Product
A subatomic particle with a single positive electrical charge, with a mass of about 1.7×10-24 g, found in the nucleus of an atom
Proton
An isotope (an atomic form of a chemical element) that is unstable; the nucleus decays spontaneously, giving off the detectable particles and energy
Radioactive isotope
Starting material in a chemical reaction
Reactant
A compound resulting from the formation of an ionic bond; Also called an ionic compound
Salt
A single covalent bond; the sharing of a pair of valence electrons by two atoms
Single bond
A substance that is dissolved in a solution
Solute 
A liquid that is a homogeneous mixture of two or more substances
Solution
Dissolving agent of a solution. Water is the most versatile solvent known
Solvent
The amount of heat that must be absorbed or lost for 1 g of a substance to change its temperature by 1°C
Specific heat
A measure of how difficult it is to stretch or break the surface of a liquid
Surface tension
A measure in degrees of the average kinetic energy (thermal energy) of the atoms and molecules in a body of matter
Temperature
Kinetic energy due to the random motion of atoms and molecules; energy in its most random form. See also heat
Thermal energy
An element indispensable for life but required in extremely minute amounts
Trace element
The bonding of a given atom; the number of covalent bonds an atom can form, which usually equals the number of unpaired electrons in its outer most (valence) shell
Valance
An electron in the outer most electron shell
Valance electron
The outer most energy shell of an atom, containing the valance electrons involved in chemical reactions of that atom
Valance shell
Wake attractions between molecules are parts of molecules that result from transient local partial charges
Van der Waals interaction
The number of protons in the nucleus of an atom, unique for each element and designated by a subscript
Atomic number
In a chemical reaction, the state in which the rate of a forward reaction equals the rate of the reverse reaction, so that the relative concentrations of reactants and products do not change with time
Chemical equilibrium
A water molecule that has an extra proton bound to it; H3O+, commonly represented as H+
Hydronium ion
