system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why is 70% isoprpyl alcohol better than 99%?

The title says it all.

Edit: actually the title didn't say it all. I meant a better disinfectant.
gpt
Better for what? A 70% solution of isopropyl alcohol works better as a disinfectant because bacteria close their membranes without any water around them. A bit of water in there opens up the membrames which allows the isopropyl alcohol to enter and kill the bacteria.