27 terms

Intro to Chem & Props of Matter Vocabulary

STUDY
PLAY
chemistry
the study of matter and how it changes
solids
molecules are tightly packed, have a definite shape and volume, cannot be compressed, and only vibrate a little
liquids
molecules are loosely packed, have a definite volume but do not have a definite shape, cannot be compressed, and move somewhat
fluid
a substance that flows (includes liquids AND gases)
gases
molecules are very far apart, have no definite shape or volume, can be compressed, and move very fast
colloids
substances with some characteristics of solids and some of liquids
volume
the amount of space something takes up
temperature
the average amount of energy a substance has
physical changes
changes the form of the substance but not its identity
melting
solid to a liquid by adding heat
freezing
liquid to a solid by taking away heat
vaporizing
liquid to a gas by adding heat
evaporation
vaporizing that takes place on just the surface of the liquid
boiling
vaporizing that takes place throughout the liquid
condensing
gas to a liquid by taking away heat (fog on a mirror, "sweat" on a cold can of pop)
subliming
solid to a gas or gas to a solid (no liquid phase in between)
physical property
a property that can be observed WITHOUT changing it into another substance
chemical property
a property of a pure substance that describes its ability to CHANGE into different substances
flammability
chemical property that describes how easily something catches fire and burns
pH
chemical property that describes how acidic or basic (alkali) a substance is
solubility
physical property that describes how easily something will dissolve in water
state of matter
physical property that describes whether something is a solid, liquid, or gas
texture
physical property that describes the feel of something
reactivity
chemical property that describes how easily a substance will react with another substance, ie. baking soda reacting with vinegar
base (alkali)
substance that has a pH higher than 7 on the pH scale
acid
substance that has a pH lower than 7 on the pH scale
neutral
substance that has a pH of 7