Changes and Reactions by Ashna Khemani (316),Bhavna Ramkumar (327),Alden Cam(305)Samyuta Kaligotla(313) 
Chemical Changes
Endothermic Reaction 💥
Physical Changes
Exothermic Reactions ex: candle melting
absorb energy from surrounding
Combustion equation
Defintion
C3H8 + 5O2= 3CO2 + 4H2O + 2220 kJ
more energy to break bonds in reactantas
Types of Chemical Change
Production of a gas
Change in color
energy of product greater that reactants
metal bracelet will turn dark and rusty
vinegar and baking soda
match turns black after lit
copper roof will change colors
example
wood turns black after burned
acids and carbonates
baking soda and an acid
dissolving ammonium
Examples
Reversible
Irreversible
Solid chocolate -> chocolate syrup
Water -> Ice
ice melting
Crumple shirt -> iron to make it smooth
Burning your pizza in the oven
Microwaving pizza -> Letting it sit out to cool down
endothermic and exothermic
boiling egg
Formation of a Precipitate
lemon juice or vinegar with milk
Slicing a pizza
Heating metal -> putting it in water so it cools
a solid that forms and separates from a liquid
mercury oxide heated
breaks into mercury and oxygen
Eating the pizza
Spilling pizza sauce on your white carpet
equation
Reactants---->Products
represents a chemical reaction
Substance reacts and combines into new substances
Physical properties change
Substance stays the same
Release of energy
Uses less NRG to break down
Opposite of Endothermic Reactions
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