Which room though?

The indoor temperature is always at room temperature and vice versa. It's not constant though.

Well at some point you encounter a phase change, which complicates things, but mostly the heat capacity (how much energy it takes to raise the temperature) is fairly constant. In an ideal gas it is exactly constant, but that is a bit of an approximation, even if it works quite well for most gases.

Kelvin doesn’t have degrees btw you just say 50K or 100K because it’s an absolute temperature scale as opposed to an arbitrary or relative one like Fahrenheit or Celsius. I’d expect that the energy would be double though that’s more of a feeling.

That wish just condenses the atmosphere of half of the planet for half of the time. How do you like your puddles of liquid oxygen now?

I think it's acute angle

No, it's Kur Tangle