system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why does 5ghz Wi-Fi penetrate less than 2.4ghz?

Not sure if penetrate is the right word. Basically high frequency electromagnetic waves penetrate more than low frequencies. You can see this with how x-ray machines work ( high frequency x-rays travel through flesh that visible light bounces of). But on the other hand 5ghz wifi has more problems with obstructions than 2.4ghz.

So which is it? Does higher or lower frequency penetrate more? Or is there some lowest penetrating frequency?
gpt
There are two different factors at play here.

 Both are very important and could easily be compared to am\fm radio. It's about wavelength. In the case of 2.4 vs 5 gig Hz it's more than twice the wavelength difference.

How does wavelength impact the way the energy travels?

1 the lower the wavelength the farther the energy will travel (so 2.4 gig is better there)
2 the higher the wavelength the less interruptions it will encounter as it moves thru objects (walls Windows doors clouds etc) (so 5 gig is "slightly" better there)

The biggest improvement is the increase in bandwidth by it is offset by slightly shorter range. 

But both are up in the gig spectrum meaning they are not going to travel very very far unless you have a really powerful amplifier connected to your wireless router. (Which would be very dangerous for other reasons)