How many neutrons does element x have if it's atomic number is 23 and its mass number is 70

The number of neutrons is 47

Explanation:

In order to find the number of neutrons we subtract the atomic number from the atomic mass.

In the given case the atomic number is 23 and mass number is 70 so

No of neutrons is 70 -23 = 47

If the heat engine is a perfect carnot cycle engine, thenefficiency = (t2-t1)/t2   where t1=temperature of cold reservoir ( ° k) = 135            t2=temperature of hot reservoir ( ° k)   = 325thereforeefficiency = (t2-t1)/t2 = (325-135)/325 = 0.5846 = 58%  note: this is the theoretical maximum efficiency of a perfect heat engine.   real-life engines do not achieve this value.