Answer:
no they are always working especially when sleeping becuase the body isnt using excess energy
A little trick i learnt: The atomic number reflects how many electrons there are, and there must be an equal charge. therefore, there are the same amount of protons as there are electrons. so if it has 81 protons, we look for number 81 in the periodic table, Thallium
Light speed in water is 2.25 times 10^5 m/s so the index of refraction is higher than the index of refraction of light in a vacuum which is 1.0. (speed in vacuum for light is 300,000 km/s)
Index of refraction of light in water is 3.0 time 10^5 m/s divided by 2.25 times 10^5 m/s = 1.33.
Hope this is what you wanted.
B, proton is positive and it does not represent the symbol