Does your 2000 silverado have a ignition key transponder?
My 2000 Silverado (if I had one!) would likely have a Passive Anti-Theft System (PATS), which uses a transponder key. GM started phasing in PATS in the late 1990s, and by 2000, it was fairly standard on most models. So, yes, it's highly probable a 2000 Silverado would have a transponder chip in the ignition key.