Is it true the less mass or the less chemicals that are in suns the longer they live

Which accounts for an increase in the temperature of a gas that is kept a constant volume

If anyone who can me with this hw? i would really appreciate it

Adielectric-filled parallel-plate capacitor has plate area a = 30.0 cm2 , plate separation d = 9.00 mm and dielectric constant k = 3.00. the capacitor is connected to a battery that creates a constant voltage v = 15.0 v . throughout the problem, use ϵ0 = 8.85x10-12 c2/n.m2 . find the energy u1 of the dielectric-filled capacitor.