 Matter is made of atoms and molecules (your book refers to these as particles)

 Atoms are the smallest particles of elements. › They are made of protons, neutrons, and electrons  Atoms can combine to form compounds or molecules.  Compounds are two or more elements chemically combined in a specific ratio (i.e. H 2 O  2 hydrogens to 1 oxygen [2:1 ratio])

 Molecules are made up of atoms combined in specific ratios › i.e. Hydrogen gas: H 2  Every combination of atoms is a molecule. › In this example, two hydrogen atoms make a molecule of hydrogen gas. BUT….  not all molecules are compounds › Since Hydrogen gas only contains the element Hydrogen, it’s not a compound In conclusion, all compounds are molecules but not all molecules are compounds

 A state of matter that has a definite shape and volume.  The particles are very close together and have strong intramolecular attractions that hold them together  The particles move, but not fast enough to overcome the molecular attractions (bonds) › Basically the particles vibrate in place

 State of matter that has a definite volume but no shape (it takes the shape of its container)  The particles move fast enough to overcome some of the molecular attractions so they can slide past each other

 Surface tension - think of it like an elastic “skin” of a liquid  property of the surface of a liquid that allows it to resist an external force (i.e. a water strider bug)  Has to do with cohesion (attraction) of molecules to each other more than to the air above the liquid.  mU3CLxvgU mU3CLxvgU

 Viscosity- a liquid’s resistance to flow. › The stronger the attraction between the molecules of a liquid, the more viscous it is (harder to flow) › Example: honey, syrup, molasses, etc….

 State of matter that has no definite shape or volume.  Particles move so quickly they can overcome the molecular attractions and break away from one another

 An ionized gas › This means that so much heat (energy) has been added to the molecule that the electrons break free and exist separately from ions (positively charged particles) › Examples of plasma: the sun, the Northern Lights (auroras), lightning, fluorescent lamps and neon signs › FuiM FuiM

 When we heat a substance, what happens to its molecules…

 Temperature- the average motion of molecules/ a measure of how fast the particles are moving › Measuring the kinetic energy