If the Q value of an endothermic reaction is 2.17 MeV, then the ...

[erika]

If the Q value of an endothermic reaction is 2.17 MeV, then the minimum kinetic energy needed in the reactant nuclei if the reaction is to occur must be
  1.equal to 2.17 MeV.
  2.greater than 2.17 MeV.
  3.less than 2.17 MeV.
  4.exactly half of 2.17 MeV.

Question 2

Suppose the decay constant of radioactive substance A is twice the decay constant of radioactive substance B. If substance B has a half-life of 4 h, what's the half-life of substance A?
  1.8 h
  2.4 h
  3.2 h

[lauravaras]

Answer to Question 1

2

Answer to Question 2

3

[erika]

Thanks for the timely response, appreciate it

[tuate]

Gracias!