Continuous Theory of Matter
The theory that all substances are essentially long, unbroken blobs of matter. They can be cut in half over and over.
Discontinuous Theory of Matter
The theory that everything is made of small particles, rather than long, unbroken blobs of matter.
The Law of Mass Conservation
(Developed by Antoine Lavoisier) Matter cannot be created or destroyed; it can only change forms.
Elements
Any substance that cannot be broken down (decomposed) into simpler components.
Metals
Elements that are malleable, have luster
(are shiny), and are able to conduct electricity.
Nonmetals
Elements that are brittle, lack luster (are not shiny), and do not conduct electricity.
What is hydrogen?
A nonmetal (despite being in the metal section of the Periodic Table).
Metalloids
Elements that have some metal properties and some nonmetal properties.
Compounds
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.
Law of Multiple Proportions
If 2 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.
Molecules
The groups that are formed when atoms join together to form compounds.
Ionic Compound
A compound that contains at least one metal atom and at least one nonmetal atom.
Covalent Compound
A compound made solely of nonmetal atoms.
Pure Substance
A substance that contains only one element or compound.
Homogeneous Mixture
A mixture with a compositions that is always the same no matter what part of the sample is observed (Dr. Pepper, salt water).
Heterogeneous Mixture
A mixture with a composition that is different depending on what part of the sample is observed (Italian Dressing, cereal and milk, etc).
