atom - ANSWER- A submicroscopic particle that constitutes the fundamental building block of ordinary
matter; the smallest identifiable unit of an element.
molecule - ANSWER- Two or more atoms joined chemically in a specific geometrical arrangement.
chemistry - ANSWER- The science that seeks to understand the behavior of matter by studying the
behavior of atoms and molecules.
hypothesis - ANSWER- A tentative interpretation or explanation of an observation. A good one is
falsifiable.
experiment - ANSWER- A highly controlled procedure designed to generate observations that may
support a hypothesis or prove it wrong.
scientific law - ANSWER- A brief statement or equation that summarizes past observations and predicts
future ones.
law of conservation of mass - ANSWER- A law stating that matter is neither created nor destroyed in a
chemical reaction.
atomic theory - ANSWER- The theory that each element is composed of tiny indestructible particles
called atoms, that all atoms of a given element have the same mass and other properties, and that
atoms combine in simple, whole-number ratios to form compounds.
scientific method - ANSWER- An approach to acquiring knowledge about the natural world that begins
with observations and leads to the formation of testable hypotheses.
, matter - ANSWER- Anything that occupies space and has mass.
substance - ANSWER- A specific instance of matter such as air, water, or sand.
state - ANSWER- A classification of the form of matter as a solid, liquid, or gas.
composition - ANSWER- The basic components that make up matter.
solid - ANSWER- A state of matter in which atoms or molecules are packed close to one another in fixed
locations with definite volume.
liquid - ANSWER- A state of matter in which atoms or molecules pack about as closely as they do in solid
matter but are free to move relative to each other, giving a fixed volume but not a fixed shape.
gas - ANSWER- A state of matter in which atoms or molecules have a great deal of space between them
and are free to move relative to one another; lacking a definite shape or volume, this conforms to those
of its container.
crystalline solid (crystal) - ANSWER- A solid in which atoms, molecules, or ions are arranged in patterns
with long-range, repeating order.
amorphous solid - ANSWER- A solid in which atoms or molecules do not have any long-range order.
pure substance - ANSWER- A substance composed of only one type of atom or molecule.
mixture - ANSWER- A substance composed of two or more different types of atoms or molecules that
can be combined in variable proportions.