States of Matter

Particle Models of Solid, Liquid, & Gas 4 States -states (or phases) of matter are the physical forms in which a substance can exist EX. Water: solid(ice), liquid(water) or gas(vapor) -matter exists in 4 familiar states: solid, liquid, gas, plasma -state of a substance depends on A. the motion of its particles (atoms & molecules) B. how strongly they are attracted to one another -called Brownian motion Particle Models of Solid, Liquid, & Gas

Solids -solid : the state in which matter has definite shape and volume -particles held tightly in place and vibrate -do not move fast enough to overcome the force of attraction between them -two basic types of solids: Crystalline - orderly, 3-D arrangement of atoms or molecules (repeating pattern of rows) EX: iron, diamond, ice, salt Amorphous - atoms or molecules are in no particular order (no organized pattern) EX: rubber, wax, glass, cotton candy

Liquids -liquid : the state in which matter takes the shape of its container and has definite volume -particles slide past one another -move fast enough to overcome some of the attraction between them -particles are already close together, so it is hard to push them closer -ideal for hydraulic systems like the brakes on a car -surface tension & viscosity are two more important properties of liquids

Surface Tension -the force acting on the particles at the surface of a liquid -causes the liquid to form spherical drops -different for different liquids EX: isopropyl (rubbing) alcohol has a lower surface tension than water, but mercury has a higher surface tension than water A water strider using surface tension to "stand" on the water's surface Water beading on a leaf Surface tension keeps the coin afloat in the glass of water

Viscosity -viscosity : a liquid's resistance to flow -stronger attraction between the particles = higher viscosity EX: honey & water - honey flows much more slowly than water because it has higher Honey can be drizzled over the biscuit because it has a moderate viscosity. Motor oils have a fairly high viscosity so they don't break down under the heat and friction generated by the moving parts of an engine.

Gases -gas : the state in which matter changes in both shape and volume -particles move independently of one another -move fast enough to overcome almost all of the attraction between them -change shape and volume to fit their container -larger number of gas particles in a container = more particles collide with each other and with the inside of the container -result is increased pressure (the amount of force exerted on a given area)

Boyle's Law & Charles's Law Behavior of Gases -gases do change volume to fit their container, but pressure and temperature affect the volume of gases -2 laws describe the behavior of gases with respect to pressure and temperature: Boyle's Law & Charles's Law

Boyle's Law (pressure) -states that for a fixed amount of gas at a constant temperature, the volume of the gas increases as pressure decreases and volume decreases as pressure Increases -meaning: pressure goes up, volume goes down pressure goes down, volume goes up

Charles's Law (temperature) -states that for a fixed amount of gas at a constant pressure, the volume of the gas increases as temperature increases and volume decreases as temperature decreases -meaning: temperature goes up, pressure goes up temperature goes down, pressure goes down

Plasmas -plasma : the state of matter that does not have definite shape or volume and in which particles have broken apart -estimated that 99% of known matter in the universe (mainly stars) is made of plasma -plasma occurs when particles become highly excited or ionized -conduct electric current and can be contained by electric and magnetic fields -EX: Natural plasmas - lightning, fire, auroras Artificial plasmas - fluorescent lights, plasma tv’s, plasma balls

This diagram compares the 4 states of matter we discussed. See what Tim & Moby have to say about matter Increasing Energy