What sign does the change in enthalpy have when the reaction releases heat energy to the surrounding?

Firms use marginal analysis to determine prices by a) changing prices in accordance with information from retailers. b) using comparisons with strong competitors to position prices accordingly. c) examining the effect on revenue of small changes to the price of one item. d) trying to minimize production costs by using better and more efficient methods.

Explain the popular saying "we are made of stardust. how are we made of stardust? use scientific vocab.

All of the following physical reactions occur when our fight-or-flight response is triggered  except  a.dilating pupilsb.increasing heartbeatc.increasing digestiond.increasing perspiration  select the best answer from the choices providedabcd