Answer:
when the water is heated with immersion heater, the water becomes less dense due to which the warm water rises up and the cooler water fills it's space.
Their atomic number?? (easy guess)
Answer:
%
Explanation:
We have given cooler temperature that is
= 6°C =273+6=279 K
And the warm temperature of water that is 
The maximum possible efficiency is given by 
So maximum efficiency
%