QUICK ANSWER
J.J. Thomson's cathode ray experiment was a set of three experiments that assisted in discovering electrons. He did this using a cathode ray tube or CRT. It is a vacuum sealed tube with a cathode and anode on one side.
Answer : The heat your body transfer must be, 25.1 kJ
Explanation :
Formula used :

or,

where,
Q = heat = ?
m = mass of water = 500.0 g
c = specific heat of water = 
= initial temperature = 
= final temperature = 
Now put all the given value in the above formula, we get:


Therefore, the heat your body transfer must be, 25.1 kJ
breaking bonds in reactants and forming new bonds in products. Breaking bonds requires energy, and forming bonds releases energy.