0.250 moles of gas are in a piston. The gas does 109 J of work while 240 J of heat are added. What is the change in internal energy? (Be careful with + and - signs. +W = expansion, +Q =added, +ΔU = temp goes up)

Thank you!

+131Joules

Explanation:

Energy can be expressed using below expresion.

ΔE = (q + w)eqn(1)

q will be + be if heat is gained hence, q= 240 J

work "w" will be - ve if work is done by the system, hence w= -109 J

Then substitute into eqn(1)

Change in Internal energy=

= (240 -109 )

= +131J

we need answer choices

a.   mass number from atomic number