Biology 1 Chapter 2 Flashcards

acid

Molecule that donates hydrogen ions and increases the concentration of hydrogen ions in a solution.

adhesion

Attraction between water molecules and other molecules.

anion

Negative ion that is formed by an atom gaining one or more electrons.

atom

The smallest unit of matter that retains all of the chemical properties of an element.

atomic mass

Calculated mean of the mass number for an element’s isotopes.

atomic mass number

Total number of protons and neutrons in an atom.

atomic number

Total number of protons in an atom.

balanced chemical equation

Statement of a chemical reaction with the number of each type of atom equalized for both products and reactants.

base

Molecule that donates hydroxide ions or binds excess hydrogen ions and decreases the hydrogen ions’ concentration in a solution.

buffer

Substance that resists a change in pH by absorbing or releasing hydrogen or hydroxide ions.

calorie

Amount of heat required to change the temperature of one gram of water by one degree Celsius.

capillary action

Occurs because water molecules are attracted to charges on the inner surfaces of narrow structures, drawing the water to the tubes’ sides.

cation

Positive ion that is formed by an atom losing one or more electrons.

chemical bond

Interaction between two or more atoms that results in forming molecules.

chemical reaction

Process leading to rearranging atoms in molecules.

chemical reactivity

The ability to combine and chemically bond with each other.

cohesion

Intermolecular forces between water molecules caused by the polar nature of water; responsible for surface tension.

compound

Substance composed of molecules consisting of atoms of at least two different elements.

covalent bond

Type of strong bond formed between two atoms of the same or different elements; forms when electrons are shared between atoms.

dissociation

Release of an ion from a molecule such that the original molecule now consists of an ion and the charged remains of the original.

electron

Negatively charged subatomic particle that resides outside of the nucleus in the electron orbital.

electron configuration

Arrangement of electrons in an atom’s electron shell.

electron orbital

How electrons are spatially distributed surrounding the nucleus.

electron transfer

Movement of electrons from one element to another, important in creating ionic bonds.

electronegativity

Ability of some elements to attract electrons, acquiring partial negative charges in molecules.

element

One of 118 unique substances that cannot break down into smaller substances; each element has unique properties.

enantiomers

Molecules that share overall structure but differ in how the atoms are three-dimensionally placed; mirror images of each other.

equilibrium

Steady state of relative reactant and product concentration in reversible chemical reactions.

evaporation

Change from liquid to gaseous state at a body of water’s surface.

functional group

Group of atoms that provides or imparts a specific function to a carbon skeleton.

heat of vaporization of water

High amount of energy required for liquid water to turn into water vapor.

hydrocarbon

Molecule that consists only of carbon and hydrogen.

hydrogen bond

Weak bond between slightly positively charged hydrogen atoms and slightly negatively charged atoms in other molecules.

hydrophilic

Describes ions or polar molecules that interact well with other polar molecules such as water.

hydrophobic

Describes uncharged nonpolar molecules that do not interact well with polar molecules.

inert gas

Element with filled outer electron shell that is unreactive with other atoms.

ion

Atom or chemical group that does not contain equal numbers of protons and electrons.

ionic bond

Chemical bond that forms between ions with opposite charges.

irreversible chemical reaction

Chemical reaction where reactants proceed unidirectionally to form products.

isotope

One or more forms of an element that have different numbers of neutrons.

law of mass action

Chemical law stating that the rate of a reaction is proportional to the concentration of the reacting substances.

matter

Anything that has mass and occupies space.

molecule

Two or more atoms chemically bonded together.

neutron

Uncharged particle that resides in an atom’s nucleus.

nonpolar covalent bond

Type of covalent bond that forms between atoms when electrons are shared equally between them.

nucleus

Core of an atom; contains protons and neutrons.

octet rule

Rule that atoms are most stable when they hold eight electrons in their outermost shells.

orbital

Region surrounding the nucleus; contains electron(s).

organic molecule

Any molecule containing carbon, except carbon dioxide.

periodic table

Organizational chart of elements indicating each element’s atomic number and atomic mass.

pH scale

Scale ranging from zero to 14 that is inversely proportional to the hydrogen ions’ concentration in a solution.

polar covalent bond

Covalent bond that forms as a result of unequal electron sharing, creating charged regions.

product

Molecule that is the result of a chemical reaction.

proton

Positively charged particle that resides in the atom’s nucleus.

radioisotope

Isotope that emits radiation comprised of subatomic particles.

reactant

Molecule that takes part in a chemical reaction.

reversible chemical reaction

Chemical reaction that functions bidirectionally; products may turn into reactants.

solvent

Substance capable of dissolving another substance.

specific heat capacity

The amount of heat one gram of a substance must absorb or lose to change its temperature by one degree Celsius.

surface tension

Tension at the surface of a liquid that prevents the molecules from separating; created by cohesive forces.

valence shell

Outermost shell of an atom.

van der Waals interaction

Very weak interaction between molecules due to temporary charges.