What is δe in kj for a system that receives 1.79 kj of heat from surroundings and has 4.51 kcal of work done on it at the same time. 1 cal = 4.184 j.

20.7 kJ

Explanation:

According to first law of thermodynamics:

=Change in internal energy

q = heat absorbed or released

w = work done or by the system

w = work done on the system=  {Work is done on the system is positive as the final volume is lesser than initial volume}

w = 4.51 kcal =    (1kcal = 4.184kJ)

q = +1.79 kJ   {Heat absorbed by the system is positive}

Thus for a system that receives 1.79 kJ of heat from surroundings and has 4.51 kcal of work done on it at the same time is 20.7 kJ

the number of protons in the nucleus of a given element. has slight luster and conducts electricity at high temperatures like metal.but like a nonmetal,boron is brittle and does not conduct electricity well at low temperatures. in graphite, carbon is a soft,brittle solid.it is reflective,ductile,or malleable.