2006 chevy trailblazer, gas ligt say empty and its not?

[Future WWE Diva]

Put gas in and it says its empty and then the emission light comes on.

[Do You Buy American?]

The way that gas gauges in boats work is by a float on a lever, and I assume that it is similar in cars. No idea why the float wouldn't work.

And what is the emission light? Maybe I've just never heard of it but I have never seen an emission light.