Calculate the work engergy gained or lost by the system when a gas expands from 35 to 55 l against a constant external presure of 3atm.

 The work energy lost by the system is -6078 Joules

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 by the system=  {Work is done by the system as the final volume is greater than initial volume and is negative}

where P = pressure = 3 atm

= change in volume = (55-35) L = 20 L

w =  

{1Latm=101.3J}

Thus work energy lost by the system is -6078 Joules

n has four pairs of electrons in the valence shell, electrons repel one another ,n has 7 protons in its nucleus, and since n has 7 protons, it must fill the second shell, giving it 4 pairs of electrons. the electrons form 3 bonds and 1 lone pair of electrons. each pair of electrons repels the other pairs, so they are equally far apart.

so all of the above

the density(ratio between mass and volume as m/v) decreases from top to bottom in periodic table group as the size increases and nuclear charge decreases. but in periods density increases from left to right as atom size decreases and nuclear charge increases.