Give an example of number 14 in real life?

c. heat could easily travel through the molecules in the air and escape/enter the flask. removing the air slows down the heat transfer.  

answer: enthalpy

explanation:

for a exothermic reaction, the energy is released i.e. the energy of the products is lower than the energy of the reactants.

= enthaply

= energy of products

= energy of reactants

as , thus comes out to be negative. negative value of enthalpy shows that the reaction is exothermic.

a saline water is fed to a reverse osmosis unit at flow rate o rotameter connected to reject (retentate) line reads 8 installed in reject and permeate line reads 15.2 milli siemens/cm and 300 micro siemens/com respectively.

i think it's c. if you look search electronic symbol on google and then click on wiki it shows you a