The first law of thermodynamics is as follows: ∆u=q-w , which means in a system is equal to added, minus done by the system. the units for these variables are in .

this is first law of thermodynamics in which meaning of each term is given as

= change in internal energy

Q = Heat given to the system

W = work done by the system

so here we will have

∆U=Q-W , which means Change in internal energy in a system is equal to heat given added, minus work done by the system. the units for these variables are in joule .

this is a good question! i'll do some research and come back when i have the answer!

answer;

d. are made mostly of liquid

explanation;

-the general   composition and structure planets includes; they have a thick gas and liquid layer covering a small,solid core. mostly the gases are hydrogen and helium atmosphere and layers of liquid hydrogen. for instance neptune and uranus are examples of the outer planets, they have a core covered by ice and ammonia.

-neptune's atmosphere is hydrogen and helium with a bit of methane so there is no oxygen to breath and the interior is made up of frozen water and ammonia with a rock and iron core. thus, there is no liquid water or solid surface to survive.