Searching for this question, I found the options on the internet.
"1.<span />Two atoms share electrons so they can fill their outer shells<span>2.The constant motion of electrons and the creation of charge imbalances bonds two molecules together3.A hydrogen atom with a slight positive charge is attracted to a negative charge of another molecule or atom4.One atom loses one or more electrons and the other atom gains one or more electrons"
The correct answer would be number 1. A covalent bond is achieved when two atoms share electrons from their outer shell so that they have a full outer shell leading to the electronic configuration balance they need.</span>
It is a mixture because the compounds that make up air e.g. oxygen (o2), Carbon dioxide (co2) and the most important Nitrogen which is an element and makes up 78.09% of air are not chemically bound in the way that compounds are because they can be separated easily and there has been no change in state to any of the compounds or elements in air!hope this helpful!
My thought would be B) gases.
I could be wrong but that's what i'd say