Radioactive Decay: Polonium-210 has a half-life of 140 days. Suppose a sample of this substance has a mass of 300 mg. (a) Find a function m(t) = m02 (− t h ) that models the mass remaining after t days. (b) Find a function m(t) = m0e −rt that models the mass remaining after t days. [Remember: r is the relative decay rate, and can be calculated from the half-life] (c) Find the mass remaining after one year. (d) How long will it take for the sample to decay to a mass of 200 mg?

definition

                    entropy is a measure of the randomness or the extent of disorder of a chemical process.

                      enthalpy is a measure of the heat change of a reaction occurring at a constant pressure.

measurement units:

                        entropy is measured in joule per kelvin (jk⁻¹)   whereas enthalpy is measured in joule per mole (jmol⁻¹)

requirements:

                            entropy has no requirements or limits, and its change is measured by the division between the heat change of the chemical process and the temperature.

                              in contrast, enthalpy can only be related to the heat change of the reaction under standard conditions.

i think its 5049.

i hope this !