Answer:- 71.7 calories
Solution:- it is a unit conversion problem where we need to convert joules into calories.
The unit conversion for these energy units is:
1 calorie = 4.184 joule
The given energy is 300 joules and has to be converted to calories. We will show the set up using dimensional analysis.

= 71.7 calories
So, the energy in calories is 71.7.
It would begin osmosis on it. If you put it in vinegar for example water would begin to seep through the membrane.
Cu (s) + 2AgNO3 ---> 2Ag + Cu(NO3)2
=13.5 moles Silver Nitrate
The answer is 2.37 x10^22 atoms