Chapter 1: Foundations Flashcards
chemistry
the study of matter and its changes
matter
anything that has mass and takes up volume
composition
the simple components that make up a material
structure
the composition and arrangement of a material
atoms
a small unit of matter
element
a substance that is made up of only one type of atom
compound
a substance composed of more than one element bound together in a fixed ratio
molecule
group of atoms that are held tightly together
pure substance
material that is composed of only one element or compound
mixture
a substance containing more than one substance
homogeneous mixture
a mixture that is uniform in composition; components are evenly distributed and not easily distinguished
heterogeneous mixture
a mixture in which different materials can be distinguished easily
solid
a state of matter in which the object has a definite shape and volume
liquid
a state of matter in which the object has definite volume but no definite shape
gas
a state of matter in which the object has no definite shape or volume
melting
the change of state from a solid to a liquid
vaporization
the change of state from a liquid to a gas
condensation
the change of state from a gas to a liquid
freezing
the change of state from a liquid to a solid
physical property
a characteristic that can be observed or measured without changing the identity of the substance (e.g., color, temp, mass, volume, shape, etc.)
physical change
a change in a substance that does not change its identity
chemical property
the ability of a substance to undergo a specific chemical change (e.g. flammability)
chemical change
a change that occurs when one or more substances change into entirely new substances with different properties
energy
the ability to do work or cause change
potential energy
stored energy
kinetic energy
energy of motion; the faster an object is moving, the greater the kinetic energy it has
heat energy
a type of kinetic energy involving the movement of particles within a substance
high-energy form
something that has high energy and can bring about a change
exothermic change
a physical or chemical change that releases heat energy (ex. wood burning on a campfire)
endothermic change
a physical or chemical change that absorbs energy
scientific method
a cyclical process of making observations, formulating new ideas, and testing those ideas through experiments
hypothesis
a tentative explanation that has not been tested
theory
an idea that is supported by experimental evidence
scientific law
a statement that describes what scientists expect to happen every time under a particular set of conditions
