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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
The force applied to an object times the distance that the object travels parallel to that force
A description of the natural world that has been confirmed by an enormous amount of data
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 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
Discontinuous theory of matter
The idea that substances are composed of tiny, individual particles like grains of sand
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.
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.
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
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
A process by which one or more substances change into one or more different substances
The process by which a solid turns directly into a gas, without going through the liquid phase
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.
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 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
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.
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
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.
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
A model that said the atom is made of a dense, postively-charged nucleus with electrons orbiting the nucleus in circles
Particle/Wave Duality Theory
The theory that light sometimes behaves as a particle and sometimes behaves as a wave
Another term for light, including all wavelengths, both visible and not visible
The cells on the eye's retina that detect different energies of light. These cells are responsible for our ability to see colors.
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
Quantum mechanical model
The modern-day model of the atom in which electrons whirl around the nucleus in various paths called "orbitals."
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.
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