Heat and Matter Part 2

DID YOU KNOW?? All matter can exist as ________, _______, or _________ if the temperature is right? For example: Don’t forget- The state of a substance depends on 2 things: _________ & ____________________________________ Earth, Cicero: 20°C Venus: 425 °C Neptune: -210 °C LeadSolidLiquidSolid OxygenGasGasLiquid solid gas liquid temperaturethe amount of attraction between its particles

Phase Changes MeltingFreezingEvaporationCondensation Change from liquid to gas Change from solid to liquid Change from gas to liquid Change from liquid to solid

Melting and Freezing The temperature at which a substance changes from a solid to a liquid is called the _______________ The temperature at which a liquid changes from a liquid to a solid is called the _______________ Melting point Freezing point

When heat is added to a solid its particles move ______. Eventually they are moving fast enough to “break free” and _______ the _____ between them. When this happens, the substance _________. During melting, energy is __________ so you’ll see no rise in temperature. time Temp. faster loosen bonds melts absorbed

Solid + Energy = ? When energy is added to solids, they become liquids! Examples?

For freezing, the process is the same, just reversed. The particles ___________, the bonds pull the particles ____________ and the material ____________. During freezing, energy is ___________. slow down together freezes released

See it Happen… nimations/chang_7e_esp/enm1s3_4.swf nimations/chang_7e_esp/enm1s3_4.swfwww.mhhe.com/physsci/chemistry/a nimations/chang_7e_esp/enm1s3_4.swf

Energy determines the state!

Boiling and Evaporation When a substance changes from a liquid to a gas it _________. The temperature at which this happens is called the ____________. The bonds between the particles need to be ____________ so energy is __________ during the phase change. Oxygen boils at about -183°C. Since our temperatures on Earth are well above that, Oxygen is a ____________ on Earth. Oxygen boils at about -183°C. Since our temperatures on Earth are well above that, Oxygen is a ____________ on Earth. evaporates boiling point loosened/brokenabsorbed gas

Real Life Example When you boil water, the particles heat up and move ____________ The water stays in __________ because the particles have enough ___________ to keep them there. At the boiling point, _______ the particles have enough _______ to break free and become a _____________,they just need to get up to the __________ to “get free” (convection currents in the water help them get there). faster liquid form attraction all energy gas top/surface

Then why do puddles on the pavement go away? Water _________ have to boil to change to a gas. It can ___________ into a gas but only at the ______________ of the liquid. doesn’t evaporate surface

Quick Write! Are evaporation and boiling the same thing? Explain why or why not. No, they aren’t the same thing, because at the boiling point all particles can get enough energy to escape. With evaporation, only the ones at the surface can break away.

Condensation When fast moving particles in the air collide with a cool surface, they _______ ________. The particles slow down and move ________ ____________. When they’re close enough attraction takes over. The vapor becomes a ___________________which sticks to the cooler surface from the air. This change of state from gas to a liquid is called _____________. Examples: Dew- moisture from the _____ that _________ overnight. Dew- moisture from the _____ that _________ overnight. Clouds- water vapor condenses around a _________ particle. Clouds- water vapor condenses around a _________ particle. Steam on a mirror- water in the steam condenses on the _________ glass of the mirror when you take a shower Steam on a mirror- water in the steam condenses on the _________ glass of the mirror when you take a shower And my personal favorite…. The “sweating” glass And my personal favorite…. The “sweating” glass loseenergy closer together liquid / water drop condensation aircondenses dust/dirt cooler

Water vapor in the air bounces off the cool glass and transfers some of it’s energy to the cool glass. As this continually happens, the water vapor eventually loses enough energy that the bonds take over and it condenses into liquid water… ON THE GLASS So does the water come from inside the glass??? It’s not magic water that can go through glass. It’s water in vapor form that’s already in the air! Plus, don’t you get condensation on closed containers?? SURE YOU DO! The water comes from the air. NO!!!!

Lesson 4- Solutions, Solubility, and Chemical Reactions Forming Solutions If you mix salt and sand, the two substances form a _______. With a mixture, you can still see the substances that made it up. But, if you mix salt with water, the salt seems to __________. As the salt mixes with the water, it _________. The salt and water form a _________. A substance that dissolves other substances is a ___________. The substance that is dissolved is the __________. Water is a very popular solvent, but many solutions are made with solvents other than water. These include: mixture disappear dissolvessolution solvent solute Solution of solids- metals like stainless steel vinegar

Concentration and Solubility The measure of the amount of solute dissolved in a solvent is called _________. Solutions can be described as ______________ or ______________. If there is only a little solute compared to the amount of solvent then the solution is _______. Solutions with a lot of solute compared to the amount of solvent are considered _____________. concentration concentrateddilute concentrated