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!
4, 3, 1
Explanation:
Sb has four on the right, so it needs four on the left. It's all alone, so <u>4</u>.
O2 comes in pairs, so you only need <u>3</u> of those to get six oxygens.
And 1 is the place holder for the right side since we got the left to match perfectly.
Ionic bonds hold NaCl together
