chemistry 3

• heat moves by direct contact • from hot to cold • ex: metal spoon in hot soup gets hot

• thermal equilibrium • equal temperature

• you must cause a chemical change to see it • ability to burn • ability to rust • reactivity with oxygen

chemical property

• bonds break • bonds form • electrons move • the result is new substances

• temperature • pressure • concentration • surface area

• speeds reaction up

• slows reactions down

• reactants on the left side (what start w) • products on the right side of the (what u end with)

big numbers infront of formulas tells you how many moles (unit used to count particles ex: 2H2 + O2 = 2h2o means 2 hydrogen + 1 oxygen make 2 water

• matter is not created or destroyed • same number of atoms on both sides, atoms just rearrange

the equation is unbalanced

• count atoms on both sides • change coefficients only • use whole numbers • keep adjusting until atoms match

• combination (synthesis) • decomposition • single replacement reactions • double replacement reactions • combustion reactions

• two or more substances combine • make ONE product • A + B = AB • hydrogen + oxygen = water

• one substance breaks apart • makes two or more products • AB = A + B

energy, usually heat or electricity

• decomposition is a chemical change • separation just separates mixtures (no chemical change)

• one element kicks out another element in a compound • A + BC = B + AC • one element switches places • metals usually replace metals

• two compounds swap ions • AC + BD = AD + BC • formation of water, solid, gas

• acid donates proton • base accepts proton • results in salt + water

• this is burning • need fuel + oxygen • often get heat, light and new compounds • wood + oxygen = CO2 + water + energy • often exothermic (releases energy)

• minimum energy needed to start a reaction • without enough activation energy, no reaction happens

• lower activation energy • not used up • not permanently changed • don’t change the final products