Answer:
It's nitrogen
Explanation:
cuz it has valence 3 and a diatomic gas at room temperature
Answer:
A catalytic converter changes nitrogen dioxide to nitrogen gas and oxygen gas is a chemical change.
Explanation:
Hello.
In this case, since physical changes do not modify the molecular composition and structure of the material undergoing it whereas the chemical change does, for catalytic converters we should know they promote chemical reaction in which the composition is changed; for instance, for the given example, the following chemical reaction is the evidence:

As you can see, nitrogen and oxygen are no longer bonded but separated by themselves, therefore, this is a chemical change.
Best regards.
None of the choices are right
Hey there!
Static electricity is a missing charge. When positive ions are formed (where an electron is missing), this imbalance is called static electricity.
Gravity is<span> a very important force. Every object in space exerts a </span>gravitational<span> pull on every other, and so </span>gravity influences<span> the paths taken by everything traveling through space. It </span>is<span> the glue that holds together entire galaxies. It keeps </span>planets<span> in orbit.
Hope this helps.</span>