Vocabulary
This is the starting substance in a chemical reaction.
Reactant
A reaction that combines substances into one product.
Synthesis
This type of reaction releases heat.
Exothermic
A way to show a chemical reaction using symbols and formulas.
Chemical equation
Balance: H₂ + O₂ → H₂O
2H₂ + O₂ → 2H₂O
This is the substance formed after a chemical reaction.
Product
A reaction where one element replaces another.
Single Replacement
This type of reaction absorbs energy.
Endothermic
Why must equations be balanced?
To follow the Law of Conservation of Mass
Na + Cl₂ → NaCl
2Na + Cl₂ → 2NaCl
A number placed in front of a chemical formula.
Coefficient
AB + CD → AD + CB is what type?
Double Replacement
Energy needed to start a reaction.
Activation Energy
In H₂O, this is what H₂O represents.
chemical formula
Mg + O₂ → MgO
2Mg + O₂ → 2MgO
A reaction where one substance breaks into simpler substances.
Decomposition
A reaction that involves oxygen and burning.
Combustion
A substance that speeds up a reaction without being used up.
Catalyst
In the equation 2H₂ + O₂ → 2H₂O, what does the “2” represent?
Number of molecules (coefficient)
Fe + O₂ → Fe₂O₃
4Fe + 3O₂ → 2Fe₂O₃
A protein that acts as a catalyst in living things.
Enzyme
Breaking water into hydrogen and oxygen is what type?
Decomposition
A substance that slows or stops a reaction.
Inhibitor
What law states matter is not created or destroyed?
Law of Conservation of Mass
Why can’t you change subscripts when balancing?
It changes the substance/compound