The image shows a piston system where gas is compressed

Explain which atom l or m is more stable and why

Sum of brother and sisters age is 26. four times the brothers age is subtracted from three times the sisters age, the difference is 8. what are the ages of the brother and sister?

What is the enthalpy of combustion (per mole) of c4h10 (g)? –2,657.5 kj/mol –5315.0 kj/mol –509.7 kj/mol –254.8 kj/mol