system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5 Why does butane gas apear to be liquid in disposable  lighters?
gpt
Because butane is liquid in the lighter.  

As far as a five year old is concerned, matter has 3 states:

- Solid
- Liquid
- Gas

Now, you know from water, that if you cool liquid down, it freeze and becomes ice (solid).  If you heat water up, it becomes gas (Boils).  So, we all know that temperature impacts the state of matter.  What a lot of five years don't know is that pressure also effects matter.  

So, if you put a gas under pressure, it will become liquid at a higher temperature than it would normal.  If you continue to keep the pressure high, and drop the temperature, it will freeze a higher temperature than you're used to.  The inner core of the earth is ~9,800 °F, but is in a solid state because the pressure is SO high.  

Likewise, in a vacuum (lower pressure), matter is more volatile and will become liquid or gas quicker.  Astronauts who have had accidents in low pressure chambers have reported feeling their spit boil off their tong.  It didn't get very hot in there, it just had very very low pressure.  

So, inside you lighter, the pressure is higher than the air around us.  That extra pressure keeps the butane liquid at room temperature.