Matter & Energy

Key Terms Matter - Anything that has mass and volume Mass – the amount of matter in an object (how much stuff it’s made of) Volume – the amount of space the matter occupies (how big it is)

Energy - the ability to do work Work - using force to move something

Matter and Energy are Conserved Law of Conservation of Matter – matter cannot be created or destroyed It can be changed from one form to another Law of Conservation of Energy – Energy cannot be created or destroyed

Example of Conservation of Mass & Energy Generators produce electricity. Are they creating energy? What is the generator using to make electricity? Is electricity the only form of energy created by the generator?

Example of Conservation of Mass & Energy When a gasoline powered generator has burned up all the gas in the tank, has matter that was in the gasoline been destroyed? What happened to the matter in the gas? If 5kg of gasoline is burned how much smoke and exhaust is produced?

Kinetic Theory of Matter - 3 Parts All matter is made of tiny particles The particles are always in motion At same temperature, heavier particles move slower than lighter particles

Temperature Temperature measures the average speed of the particles within a substance Faster motion  higher temp Slower motion  lower temp

States of Matter Matter exists in 4 states Solid Liquid Gas Plasma The state of matter depends on the amount of energy

Solid Lowest energy state Slowest particle motion Particles vibrate in place Particles packed tight and stuck to each other Stuck in one shape and volume

Liquid Medium energy state Particles move faster than in solid Particles packed tight but can slide past each other Volume won’t change but shape does

Gas High energy state Particles move faster than liquid Particles are far apart and bouncing off each other Volume can change – expand and compress

Particles in Solid, Liquid & Gas

Plasma Highest energy state Particles move faster than gas Particles break apart releasing light Lightning, stars

States of Matter – Solids, Liquids and Gases Properties Energy Particles solid shape & volume stay the same lowest energy slowest motion vibrating in fixed position packed very close liquid shape changes volume stays the same medium energy medium speed sliding past each other packed very close gas shape &volume can change high energy very fast motion move in all directions far apart plasma highest energy extremely fast like gas but the particles have broken apart

Changes of State Endothermic Changes Endothermic means “heat goes in” Energy must be absorbed Melting – solid becoming liquid Evaporation – liquid becoming gas Sublimation – solid becoming gas

Exothermic Changes Exothermic means “heat goes out” Energy must be removed Condensation – gas becoming liquid Freezing – liquid becoming solid Deposition – gas becoming solid

Sublimation – Dry Ice Dry ice is frozen carbon dioxide The freezing point of carbon dioxide is negative 109.3 degrees Fahrenheit! Dry ice changes from solid directly to liquid in normal atmospheric conditions (sublimation) without going through the liquid phase, hence the name, dry ice

Endothermic or Exothermic? Gasoline evaporating into a gas Ice melting Water droplets forming on bathroom mirror Hot liquid iron changing into a solid Liquid nitrogen changing into nitrogen gas Water boiling Carbon dioxide gas turning into solid dry ice

Adding Energy to Matter speeds up particle motion OR separates particles causing a change of state As ice is heated its particles vibrate faster until it begins melting While ice melts its temp stays at 0oC until all of it has melted Once its melted the particles speed up again (temp rises)

Water Melting

Removing Energy from Matter Slows down particles OR brings them closer to each other As water vapor cools the particles slow down until they start to condense Temp will stay at 100oC until all the vapor has become liquid

http://www.kentchemistry.com/links/Matter/HeatingCurve.htm