Anything that has mass and takes up space
The metric unit of mass
A measure of the amount of matter in an object
A metric unit of volume
The metric unit of length
The metric unit of force
The English unit of mass
A method of conversion using the multiplication of fractions
A unit formed by the multiplication and/or division of other units
A device used for measuring the volume of liquids
The curved surface of a liquid, typically in a glass container
An indication of how close a measurement is to the true value.
An indication of the scale on the measuring device that was used
A digit in a measurement that is either non-zero, a zero that is between two significant figures, or a zero at the end of the number and to the right of the decimal
An object's mass divided by the volume that the object occupies
The ability to do work
The force applied to an object times the distance that the object travels parallel to that force
Energy that is transferred as a consequence of temperature differences
An educated guess that attempts to explain observations
A description of the natural world that has been confirmed by an enormous amount of data
A hypothesis that has been confirmed by experimental data
The metric unit for energy
Energy that is in motion
Energy that is stored
The First Law of Thermodynamics
Energy cannot be created or destroyed. It can only change form.
A temperature scale defined so that water freezes at 0 and boils at 100
A temperature scale defined so that water freezes at 32o and boils at 212o
The absolute temperature scale: It is not possible to reach or go below 0 Kelvin.
The process of using certain physical measurements to define the scale of a measuring device
Absolute temperature scale
The Kelvin temperature scale: It is not possible to reach or go below 0 Kelvin.
The amount of heat necessary to warm one gram of water one degree Celsius
Food calorie (Cal)
1,000 chemistry calories (cal)
The amount of heat necessary to raise the temperature of 1 gram of a substance by 1 degree Celsius
An experimental process that measures the heat released or absorbed during a chemical or physical change
An experimental device that measures the heat released or absorbed during a chemical or physical change
Continuous theory of matter
The idea that substances are composed of long, unbroken blobs of matter
Discontinuous theory of matter
The idea that substances are composed of tiny, individual particles like grains of sand
The Law of Mass Conservation
Matter cannot be created or destroyed; it can only change forms.
The process by which a substance is broken down into its constituent elements
Any substance that cannot be decomposed into less massive substances
An element that tends to give up its electrons. Metals are found on the left side of the jagged line on the Periodic Table of Elements, with the exception of hydrogen.
An element that tends to take electrons from other elements. Non-metals are found on the right side of the jagged line on the Periodic Table of Elements. Hydrogen is also a non-metal, even though it is on the left side of the jagged line.
A substances that can be decomposed into elements by chemical means
The Law of Definite Proportions
The proportion of elements in any compound is always the same.
A quantity with no units
The Law of Multiple Proportions
If two elements combine to form different compounds, the ratio of masses of the second element that react with a fixed mass of the first element will be a simple, whole-number ratio.
The smallest chemical unit of matter
More than one atom bound together to form a compound
A notation that indicates the number of type of each element in a compound
An abbreviation for an element
A compound formed by atoms that share electrons
A compound formed by ions
A substance that contains different compounds and/or elements
A substance that contains only one element or compound
A mixture with a composition that is different depending on what part of the sample you are observing
A mixture with a composition that is always the same no matter what part of the sample you are observing
A change that affects the type of molecules or atoms in a substance
A change in which the atoms or molecules in a substance stay the same
The process by which a substance changes from its liquid phase to its gas phase
The process by which a substance changes from its gas phase to its liquid phase
The process by which a substance changes from its liquid phase to its solid phase
The process by which a substance changes from its solid phase to its liquid phase
One of three states of matter: solid, liquid, or gas
The process by which a substance changes from one phase (solid, liquid, or gas) to another phase (solid, liquid, or gas)
Kinetic Theory of Matter
The theory that the atoms or molecules which make up a substance are in constant motion, and the higher the temperature, the greater their speed
The temperature at which a substance changes from its solid phase to its liquid phase
A representation of a chemical reaction
A process by which one or more substances change into one or more different substances
A molecule composed of two identical atoms
The substances found on the right side of a chemical equation
The substances found on the left side of a chemical equation
The process by which a solid turns directly into a gas, without going through the liquid phase
A reaction that changes a compound into its constituent elements
A reaction that starts with two or more elements and produces one compound
Complete combustion reaction
A reaction in which O2 is added to a compound containing carbon and hydrogen, producing CO2 and H2O
Incomplete combustion reaction
A reaction in which O2 is added to a compound containing carbon and hydrogen, producing either CO or C, along with H2O
A device on an automobile that converts gaseous carbon monoxide produced by the engine into gaseous carbon dioxide
The number on the periodic chart that is below an element's symbol. It represents the average mass of the atom's isotopes in atomic mass units.
The number on the periodic chart that is above an element's symbol. It represents the number of protons in the nucleus of the atom.
Atomic mass units
The mass unit used on the periodic chart: 1.00 amu = 1.66 x 10-24 g
The mass of a single molecule
A group of atoms or molecules that number 6.02 x 1023
The number of molecules or atoms in a mole: 6.02 x 1023
The process by which the amount of one substance in a chemical reaction is related to the amount of another substance in a chemical reaction
The reactant that runs out first in a chemical reaction. It determines the amount of products made.
The reactant or reactants that are left over at the end of a chemical reaction
The numbers that appear to the left of the chemical formulas in a chemical equation. They represent the number of moles of each substance.
The stoichiometric coefficients in a chemical equation relate the volumes of gases in the equation as well as the number of moles of substances in the equation.
A chemical formula that tells you a simple, whole-number ratio for the atoms in a molecule
A chemical formula that provides the number of each type of atom in a molecule
The mass of one mole of a given compound
An experimental apparatus developed by William Crookes. It consists of a glass tube filled with a small amount of gas. Electrodes in the tube allow for the passage of electricity through the gas.
Cathode ray tube
Another name for a Crooke's Tube
One of the three particles that make up the atom. It is negatively charged and orbits the nucleus of the atom
One of the three particles that make up the atom. It is electrically neutral and is in the nucleus of the atom
One of the three particles that make up the atom. It is positively charged and is in nucleus of the atom
Atoms with the same number of protons but different numbers of neutrons
The total number of neutrons and protons in an atom
The process by which the abundance of one isotope in an element is increased. This is typically used in order to make the fuel for nuclear bombs.
A constructed image of something that we cannot see with our eyes
Plum pudding model
A model that said the atom is made of a positive gel (the pudding) with negative particles (the plums) suspended in the gel
Another name for the Rutherford model
A model that said the atom is made of a dense, postively-charged nucleus with electrons orbiting the nucleus in circles
The center of the atom that contains the neutrons and protons
Particle/Wave Duality Theory
The theory that light sometimes behaves as a particle and sometimes behaves as a wave
A "particle" of light
A measure of the height of the crests or the depths of the troughs on a wave
The distance between the crests (or troughs) of a wave
The range of light wavelengths that are visible to the human eye
A measurable quantity in nature that does not change
The number of wave crests (or troughs) that pass a given point each second
The total range of wavelengths of light that come from the sun
Another term for light, including all wavelengths, both visible and not visible
The physical constant that relates the energy of light to its frequency
The cells on the eye's retina that detect different energies of light. These cells are responsible for our ability to see colors.
The cells on the eye's retina that detect low levels of light
A device that analyzes light emitted or absorbed by a substance
The process by which individual wavelengths of light emitted by a substance are analyzed. This process can be used to identify the elements in a substance.
The assumption that a physical quantity (such as energy) cannot have any value, but is restricted to have only discrete values
A specific shape that confines the position of an electron relative to the nucleus
Quantum mechanical model
The modern-day model of the atom in which electrons whirl around the nucleus in various paths called "orbitals."
The lowest possible energy state for a given substance
A notation that lists the number of electrons that occupy each orbital in an atom
The electrons that exist farthest from an atom's nucleus. They are generally the electrons with the highest energy level number.
A schematic representation of the valence electrons in an atom or molecule
Most atoms strive to attain eight valence electrons.
Another name for a Lewis structure
An atom that has gained or lost electrons and thus has become electrically charged
An element that rests in the "d-orbital" block of the Periodic Table of Elements
The process by which an atom turns into an ion by gaining or losing electrons
The amount of energy needed in order to take an electron away from an atom
A characteristic of atoms that varies regularly across the periodic chart
A measure of how strongly an atom attracts extra electrons to itself
The average radius of an atom
A shared pair of valence electrons that holds atoms together in covalent compounds
A total of four electrons shared between atoms
A total of six electrons shared between atoms
Please allow access to your computer’s microphone to use Voice Recording.
We can’t access your microphone!
Click the icon above to update your browser permissions and try again
Reload the page to try again!
Press Cmd-0 to reset your zoom
Press Ctrl-0 to reset your zoom
It looks like your browser might be zoomed in or out. Your browser needs to be zoomed to a normal size to record audio.
Your microphone is muted
For help fixing this issue, see this FAQ.