States of Matter
A _____ is a state of matter that has fixed volume, but no definite shape.
Liquid
What are Crystals?
Solids with regular geometric shapes that are formed from the regular arrangement of atoms.
What are three molecular properties we discussed in class?
Density, Elasticity, and viscosity
What does STP stand for?
Standard Temperature and Pressure
Name the four states of matter.
Solid, Liquid, Gas, Plasma
True or False: Melting point and freezing point occur at the same temperature.
True.
What two types of structures can atoms form?
Molecules and crystals
True or False: denser liquids float on top of less dense ones.
False.
What is Diffusion?
The spreading out of a gas into a container it fills.
Who used the principle of density to determine if King Hiero II's crown was pure gold?
Archimedes
A solid turns directly into a gas, skipping the liquid phase.
What causes crystals to form definite shapes?
The arrangement of atoms
The ability to stretch or compress and then return to its normal shape.
Elasticity
Graham's Law of diffusion states that the faster a gas diffuses, the _____ the density of the gas.
Lower
What is the difference between mass and volume?
Mass is the amount of matter of a substance, Volume is the space it takes up.
True or False: Plasma is the fourth and rarest state of matter
False. Plasma is the most abundant state of matter in the universe.
What are the main crystal shapes?
Cubic, Tetragonal, monoclinic, triclinic, and hexagonal
What is density?
A measure of the amount of matter in a given volume.
A gas law that states that equal volumes of gases at the same temperature and pressure contain the same number of molecules.
Avogadro's Law
What is surface tension?
Skin-like properties of a liquid's surface due to intermolecular forces.
What are two ways that substances can change physical states?
Substances can change physical state when heated or cooled, or when the energy of the particles is increased or decreased.
What are two methods of crystallization?
Evaporating a solvent, introducing a seed crystal to a supersaturated solution.
Forces that exist between molecules, which explain properties like surface tension, elasticity, and density.
Intermolecular forces
P1V1 = P2V2
Boyle's Law
If a balloon of helium is at 25 oC and hold 45 L and then is heated to 55 oC, what is the new volume of the balloon? (Use kelvin for Temperature. K = 273 + oC)
V2 = 50 L