Why is reaching activation energy necessary?
a)reactants require a minimum amount of energy to start to break a chemical bond. b)products require a minimum amount of energy to start to break a chemical bond. c)reactants must have the maximum amount of energy to start to break a chemical bond.
d) products must have the maximum amount of energy to start to break a chemical bond.

Heat energy (the total bond energy of reactants or products in a chemical reaction) speeds up the motion of molecules, increasing the frequency and force with which they collide. It also moves atoms and bonds within the molecule slightly, helping them reach their transition state.

You would be correct, boiling water does disinfect contamination.    the property of disinfecting means to kill  germs, bacteria and other pathogens or contamination  that might cause an infection or cause a person to become sickly. a couple methods of disinfecting are using soap, other cleaning supplies or by simply "boiling" the contaminate.  the reason why boiling water disinfects certain attributes is because some cells cannot survive the heat and pressure.

Contained in chromosomes which are located in the nucleus of the cell.