system
Given the following post, respond as if you're commenting on Reddit:
human
If viruses aren't alive, what do scientists mean when they say the coronavirus can live on surfaces for hours?
gpt
Scientific papers will typically say “viable” rather than alive. What they mean is that the virus is still capable of infecting cells. 

Think of a virus as a key, but a key made out of ice that is melting, at some point it will not be able to open the lock, then it is no longer viable.