Physical/Chemical Reactions
Best describes a physical change
What is changing the look or feel of the substance
Endothermic reaction
What is absorbing energy
Hydrocarbon + O₂ → CO₂ + H₂O
What is combustion
Particles are close together in a repeating order
What is a solid
Starting substance before a chemical reaction
What is Reactants
Example of physical change
What is tearing a piece of paper, breaking a pencil, and ice melting
Exothermic reaction
What is releasing energy
A + B → AB
What is synthesis
Particles are close together, but can move past each other
What is Water
New substance formed after a chemical reaction
What is Products
Chemical bonds?
What is connection that holds atoms together
Activation energy
What is initial energy needed to start a reaction
AB → A + B
What is decomposition
Particles are far apart and move the fastest
What is a gas
Enzymes
What is a biological catalyst
Evidence of a chemical reaction
What is color change, gas, smell, temp, and light
Location where energy is stored
Where is the bonds between atoms
A + BC → AC + B
What is single replacement
Liquid to a gas
What is evaporation
Job of a catalyst
What is speeding up a chemical reaction
H2O formula shows
2 hydrogen and 1 oxygen
When chemical bonds are broken
What is energy input is required
AB + CD → AD + CB
What is double replacement
Solid to a liquid
What is melting
Change that can speed up a chemical reaction
What is increase in surface area, temp, concentration, pressure, or catalyst