Chapter 2 Bio Vocab Flashcards
Atom
Smallest particle of an element that has the traits of the element
Atomic number
Number that identifies a particular element and is equal to the number of protons in
each atom of the element
Bond (chemical)
An interaction between atoms that holds the two atoms together based on events
relating to electrons in the two atoms
Chemical reaction
A rearrangement of atoms in substances that results in the production of new
substances
Compound
A pure substance that is composed of particles made of two or more elements
Covalent Bond
A bond between atoms involving sharing of a pair of electrons between the atoms
involved
Electron
A subatomic particle with negative charge, essentially no mass, and that is located in
regions around the atom’s nucleus
Element
A substance composed of only one type of atom
Energy level
Relates to the position of electrons around an atom’s nucleus; higher energy levels have
electrons with more energy and are located farther from the nucleus
Ion
A charged particle (anion = negatively charged particle; cation = positively charged
particle)
Ionic Bond
A bond between atoms involving the formation of oppositely charged ions by transfer
of electron(s) from one atom to another
Mass
A measure of how much matter an object has (measured in grams (g))
Matter
Anything with mass and volume
Molecule
The smallest particle of a covalent bond
Neutron
A subatomic particle that is located in the nucleus of an atom, has a mass of 1 amu, and
no charge
Nucleus (atomic)
The area within an atom where protons and neutrons are located
Proton
A subatomic particle that is located in the nucleus of an atom, has a mass of 1 amu, and
positive charge
Valence electron
A electron that is located in the outermost occupied energy level of an atom
Isotope
An atom that differs in its mass (and neutron #) from another atom of the same
element
Crookes tube
A glass tube filled with a pure sample of a gas that glows when power is supplied to the
tube (also known as a cathode ray tube)
Crookes tube
A glass tube filled with a pure sample of a gas that glows when power is supplied to the
tube (also known as a cathode ray tube)
Radioactive element
Any element whose nucleus is unstable and will decay
Radioactive decay
The breakdown of the nucleus of a radioactive atom; can be one of three types – alpha
particle, beta particle, or gamma
Alpha Particle
A particle with mass of 4 and charge of positive 2 that is given off during some forms of
radioactive decay
Light
A form of energy on the electromagnetic spectrum
Photon
A particle of light energy
Wavelength
The distance between a given point on one wave and the same point on the next wave;
for example, the distance from one crest to the next crest.
Frequency of Waves
A measurement of the number of waves that pass a given point during a particular
period of time (e.g., hertz = # cycles per second)
Energy
The ability to do work or cause change
Continuous Spectrum
The array of colors of light in the visible spectrum in which one color blends into the
next (e.g., a rainbow is a continuous spectrum)
Bright Line Spectrum
The array of distinct bands of colors of light that is seen when looking at light from
elements through diffraction grating glasses
Electron Orbits
Concept proposed by N. Bohr to describe the well-defined paths that electrons travel as
they circle the nucleus of an atom
Electron Orbital
Concept that describes the general regions where electrons travel as they circle the
nucleus of the atom; each orbital is associated with a certain energy level
Charge-cloud Model
Name of the modern model of the atom; involves a dense, positive nucleus surrounded
by cloud-like areas (orbitals) where electrons travel
Quantam Mechanic Model
Name of the modern model of the atom; involves a dense, positive nucleus surrounded
by cloud-like areas (orbitals) where electrons travel
Balanced Equation
Representation of the events of a chemical reaction that follows the law of
conservation of matter (reactants products)
Law of conservation of
matter
Concept that during any chemical reaction there is no creation and no destruction of
matter
Periodic table
An ordered listing of the elements in such a way as to illustrate trends and similarities
Period (on periodic
table)
A row on the periodic table; the number of the period indicates the number of occupied
energy levels in neutral atoms of those elements, and the position in the period
indicates the number of valence electrons in atoms of a particular element
Activation Energy
The amount of energy that must be absorbed by reactants in order for a chemical
reaction to proceed
Catalyst
A substance or particle that reduces activation energy of a reaction, thereby increasing
the rate of the reaction
Endergonic Reaction
A reaction in which more energy is absorbed than is released
Endothermic Reaction
An endergonic reaction in which the type of energy involved is heat energy
Enzyme
A protein catalyst
Exergonic reaction
Reaction in which more energy is released than is absorbed
Exothermic reaction
Exergonic reaction in which the form of energy involved is heat
Oxidation reaction
Reaction in which a particle LOSES one or more electrons
Reduction reaction
Reaction in which a particle GAINS one or more electrons
Reactant
The material that is present before a chemical reaction occurs
Product
The material that is formed as a result of a chemical reaction
State (of matter)
Arrangement of particles in a material; for our purposes, it may be solid, liquid or gas
