three cheers for me.
HELLO! my name is
LIYING.
I am from
3B1!
Dis blog is bout chapts
7, 8 & 9!
chapt SEVEN: Kinetic Model Of Matter
chapt EIGHT: Transfer Of Thermal Energy
chapt NINE: Thermal Properties Of Matter
ENJOY YEA..! :)
hope u'll learnt somethingggg! HAVE FUNNN!
7:40 AM
Friday, September 5, 2008
CHAPTER 9- Temp is the degree of HOTNESS and COLDNESS of a body!!! Heat is the amount of thermal energy flowing from HOTTER region to COLDER region~ Internal energy is the total energy of the particles held by strong bonds - potential energy & kinetic energyKINETIC COMPONENT--> due to vibration of particles--> the higher the temp, the more vigorous vibration is--> in liquid / gas, particles move. thus, KE is due to movementPOTENTIAL COMPONENT--> due to stretching / compressing of bond as particles vibrate--> amt stored in bond depends on force between particles and how far they areMelting & Solidification+ solid => liquid: MELTING+ melting occurs at a certain temp, it is the MELTING POINT+ melting pnt: 0 degree celcius [ice => water]+ when bonds are broken, melting occurs+ hence, the molecules are able to move out of their fixed positions + liquid => solid: FREEZING / SOLIDIFICATIONBoiling / Condensation+ liquid => gas: BOILING+ the temp where it boils is called BOILING PNT+ boiling point: 100 degree celcius [water => steam]+ molecules move apart, boiling occurs+ gas => liquid: CONDENSATION+ thermal energy is given outEvaporation+ liquid => gas: EVAPORATION!!! evaporation occurs at ANY temperature+ thermal energy is carried away+ collision of air molecules rebounds some molecules+ occurs at SURFACE of water~ experience cooling effect on skin~ puddle of water dries up~ lowers tempFactorS AffectinG RatE Of EvaporatioN1. Temperature - rise of temp increases rate of evaporation 2. Humidity of surrounding air - increasing rate of evaporation decreases rate of evaporation - rate of evaporation increases with lower humidity 3. Surface area of liquid - larger surface area, rate of evaporation increases - more molecules escapes with larger exposed area4. Movement of air - moving of air remove molecules of liquid when they escape from the surface - rate of evaporation increases when surrounding air is moving5. Pressure - reduced in pressure increases rate of evaporation6. Boiling point of liquid - liquids with LOWER bp evaporates FASTER
