What is the difference between the nitrite ion and the nitrate ion?

See below  

Step-by-step explanation:

Nitrite ion is NO₂⁻; nitrate ion is NO₃⁻.

The nitrate ion has one more oxygen atom than nitrite ion.

An -ate ion always has one more oxygen atom than an -ite ion.

You can see the structures of the two ions below.

while cooking a piece of 1/2 pound beef steak, a cast iron pan (2.4kg in weight) was heated 260 celsius.