The particulate nature of matter
Review readings, powerpoints, labs, and worksheets.
Unit 1 objectives
Students will be able to:
• apply the particulate model of matter to describing physical properties for the three states of matter and to discussing their properties (i.e. density, compressibility, etc...)
The particle model for matter states that all matter is made of particles which are moving all the time.
In solids they vibrate in place, a solid holds its shape and volume.
In liquids the particles can move all through the liquid, it pours, A liquid holds its volume but takes the shape of the container.
In a gas the particles are moving fast. A gas will spread out to fill any container, a gas does not hold its shape or volume.
• Relate macroscopic and submicroscopic representations of solids, liquids and gases.
• describe changes in kinetic and potential energy in both system and surroundings during heating or cooling processes, including phase changes, and explain the reasons for these changes at a submicroscopic level (review lab and correct any missed questions.)
• convert between units of pressure and temperature, using provided conversion factors.
• use the appropriate gas law to calculate changes in pressure, temperature and/or volume of a gas.
• describe causes for changes to gas properties (including pressure, volume and temperature) using the kinetic theory of gases.
Vocabulary terms
Matter- anything that has mass and occupies up space
Crystal lattice-In a crystal, the formation in which the particles are arranged in a solid(orderly, three dimensional , repeating pattern)
Rotational motion
Vibrational motion
Fluid- a substance that can flow
Compressible- Compressibility is the ability of something to be "squashed" into a smaller space. Gases are very compressible with relatively little pressure. Liquids are much less compressible and solids even less so
Density=Mass/volume(how full an area is)
Temperature- average kinetic energy
Maxwell-Boltzman distribution-describes the speed of particles and the interactions between them when in a gas state(only elastic collisions- An elastic collision is an encounter between two bodies in which the total kinetic energy of the two bodies after the encounter is equal to their total kinetic energy before the encounter. Elastic collisions occur only if there is no net conversion of kinetic energy into other forms.)
Absolute zero-Theoretical temp at which substances possess no thermal energy, -273.15 degrees celcius
Kelvin- temp scale freezing pt is 273, boiling pt 373
When using kelvins to solve problems add 273 to some degrees celcius
Condensation- when a gas becomes a liquid it is losing losing kinetic energy , less space between particles
Evaporation- when a liquid turns to a gas its gaining kinetic energy(endothermic) more space between particles
Vaporization
Sublimation
Deposition
Endothermic- Energy entering the substance process that absorbs heat from the surroundings
Exothermic- energy leaving the substance process that releases heat into its surroundings
Kinetic energy
Potential energy
Phase change- metamorphosis of a material or mixture from one phase to another, such as gas to liquid, solid to gas
Physical change
Boiling point
Melting/freezing point
Heating/cooling curve- the curving of temperature up/down when transitioning between states
Pure substance
Mixture
Scientific law
Scientific theory
Pressure
Torr