Changes in Matter

Physical Change: Is any change that alters the form or appearance of matter but does not make any substance in the matter into a different substance

Changes of State Physical Change A substance that undergoes a physical change is still the same substance after the change

Changes of state is a physical change (EG) Water: Spilled water is a liquid, after a few hours the puddle disappears because it evaporated into water vapor, which is a gas

Changes in Shape or Form (EG) Sugar Solution: If you allow the solution to dry out, the sugar will remain as a crust on the bottom of the pan.

Changes in Shape or Form (EG) Dissolving, bending, crushing, breaking, chopping, filtration, and distillation are physical changes

Chemical Change: A change in matter that produces one or more new substances Reaction of sulfuric acid and sugar. The acid dehydrates the sugar forming a pillar of carbon (black) and steam.

 New substances have different chemical properties than the original substances

Example of Chemical Change (EG) hydrogen peroxide is poured onto a cut, it breaks down into hydrogen and oxygen

(EG) Iron metal combines with oxygen to form iron oxide

EG) Methane gas: When it burns it combines with oxygen and forms CO2 and water vapor (EG) Combustion is a chemical change when fuel combines with air to burn

(EG) Combustion, electrolysis, oxidation, tarnishing +

Conservation of Mass Law of Conservation of Mass: Matter is not created nor destroyed in a chemical reaction, it just changes form

No mass is lost or gained after a chemical change

(EG) Methane gas: When you burn methane, the mass of the original methane gas and oxygen used, will equal the mass of the carbon dioxide and water produced

Matter and Thermal Energy Temperature and Thermal Energy 1) Energy is the ability to do work or cause change.  

Every chemical or physical change in matter includes a change in energy  

Temperature is a measurement of the average energy of random motion of particles of matter a) Warm has more energy than cold due to motion of particles

Thermal energy is the total energy of all the particles in an object

a) Flows from warmer matter to cooler matter

Temperature and Thermal energy are not the same thing, but temperature is related to thermal energy  

Thermal Energy and Changes in Matter Endothermic: a change in which energy is taken in (EG) melting of ice: Ice absorbs thermal energy from its surroundings and melts –endothermic reaction  

Exothermic: Changes in matter can also occur when energy is given off Exothermic: Changes in matter can also occur when energy is given off. It releases energy (EG) Combustion