• Time of a chemical reaction where the concentration of the reactant decreases by half o ln At/A0 = -0.693 = -kt
o t1/2 = 0.693/k
▪ Example: An isotope has a half life of 14.3 days. How long does it take for 95% of the sample to decay?
Activation Energy (Ea)
• Energy of molecular collisions reactants must have to break bonds and therefore form products
• Arrhenius Equation Don't forget about the age old question of What did weeks v united states establish?
o k = Ae-Ea/RT
▪ A- collision frequency factor
▪ R- universal gas constant (note units)
If you want to learn more check out What are autonomies and when were they established?
We also discuss several other topics like What are the four major components of the central nervous system?
▪ T- temperature in kelvin
• Steps that show how reaction occurs (molecular level) We also discuss several other topics like What is scaffold for biochemical activities?
o Elementary Step- single process
o Intermediate- species produced in one step and used in the next step
o Molecularity- number of ions, atoms, or molecules in an elementary step