Ch 281 Chapter 2

Proton donor that releases H+ (and anions) when dissolved in water.

The concentration of H+ in a water solution, as compared with the concentration of OH–.

The adherence of molecules to the walls of conducting tubes, as in plants.

A negatively charged ion.

The smallest unit that retains the chemical and physical properties of an element.

The nucleus of an atom, containing protons and neutrons.

The number of protons in the nucleus of an atom.

The weight of an element in grams, equal to the mass number.

The number 6.022 × 10²³, derived by dividing the atomic weight of any element by the weight of an atom of that element.

Proton acceptor that reduces the H⁺ concentration of a solution.

A membrane with two molecular layers.

Applications of chemical and biological knowledge to decontaminate polluted environments.

Substance that compensates for pH changes by absorbing or releasing H⁺.

The amount of heat required to raise 1 g of water by 1°C, known as a "small" calorie; when capitalized, a unit equal to 1,000 small calories.

A positively charged ion.

Link formed when atoms of reactive elements combine into molecules.

A chemical reaction written in balanced form.

The high resistance of water molecules to separation.

A molecule whose component atoms are different.

The number of molecules or ions of a substance in a unit volume of space.

Bond formed by electron sharing between atoms.

A standard unit of mass, about 1.66 × 10^–24 grams.

The separation of water to produce hydrogen ions and hydroxide ions.

Negatively charged particle outside the nucleus of an atom.

The measure of an atom's attraction for the electrons it shares in a chemical bond with another atom.

A pure substance that cannot be broken down into simpler substances by ordinary chemical or physical techniques.

Regions of space within an atom where electrons are found. Also referred to as shells.

The name of a molecule written in chemical shorthand.

The heat required to give water molecules enough energy of motion to break loose from liquid water and form a gas.

A surface coat of water molecules that covers other polar and charged molecules and ions.

Noncovalent bond formed by unequal electron sharing between hydrogen atoms and oxygen, nitrogen, or sulfur atoms.

Polar molecules that associate readily with water.

Nonpolar substances that are excluded by water and other polar molecules.

A rigid, crystalline structure formed when a water molecule in ice forms four hydrogen bonds with neighboring molecules.

A positively or negatively charged atom.

Bond that results from electrical attractions between atoms that have lost or gained electrons.

A distinct form of the atoms of an element, with the same number of protons but different number of neutrons.

The scientific unit equivalent to a Calorie and equal to 1,000 small calories.

The amount of matter in an object.

The total number of protons and neutrons in the atomic nucleus.

Anything that occupies space and has mass.

The number of moles of a substance dissolved in 1 L of solution.

Amount of substance that contains as many atoms or molecules as there are atoms in exactly 12 g of carbon-12, which is 6.022 × 10²³.

The weight of a molecule in grams, equal to the total mass number of its atoms.

A unit composed of atoms combined chemically in fixed numbers and ratios.

Uncharged particle in the nucleus of an atom.

Association that occurs when nonpolar molecules clump together.

Bond in which electrons are shared equally.

The region of space where the electron "lives" most of the time.

The numerical scale used by scientists to measure acidity.

Association that occurs when polar molecules attract and align themselves with other polar molecules and with charged ions and molecules.

Bond in which electrons are shared unequally.

An atom or molecule leaving a chemical reaction.

Positively charged particle in the nucleus of an atom.

The giving off of particles of matter and energy by decaying nuclei.

An unstable, radioactive isotope.

The atoms or molecules entering a chemical reaction

The term indicating that a reaction may go from left to right or from right to left, depending on conditions.

Regions of space within an atom where electrons are found.

The molecules of a substance dissolved in water.

Substance formed when molecules and ions separate and are suspended individually, surrounded by water molecules.

The water in a solution in which the hydration layer prevents polar molecules or ions from reassociating.

The amount of heat required to increase the temperature of a given quantity of water.

The force that places surface water molecules under tension, making them more resistant to separation than the underlying water molecules.

An element that occurs in organisms in very small quantities (< 0.01%); in nutrition, a mineral required by organisms only in small amounts.

Isotope used to label molecules so that they can be tracked as they pass through biochemical reactions.

An electron in the outermost energy level of an atom.

Weak molecular attractions over short distances.

An arrangement formed when a water molecule in liquid water establishes an average of 3.4 hydrogen bonds with its neighbors.

A measure of the pull of gravity on an object.