Help!! Chemisty Questions?

Which elements can form diatomic molecules joined by a single covalent bond?

Hydrogen & halogens only

Which is a typical characteristic of an ionic compound?

The ionic compound has a high melting point.

First question: you want to ascertain the price on the N contained in the NO3-a million and NO2-a million. understanding oxygen is two- you may discern out: In NO3-a million the N could be 5+ (3 oxygen = -6 so the N could be 5+ to make the completed element -a million). In NO2-a million the N could be 3+ (2 oxygen = -4 so the N could be 3+ tomake the completed element -a million),. So, the N is replacing from 5+ to three+. This represents a income of electrons so NO3-a million is being decreased (LEO says GER). 2d question considering that there's a double arrow both the ahead and opposite reactions are taking position. which skill B is real and C (and D) can't be real. because you don't recognize a few thing else you won't be able to make a judgement about it is more beneficial solid so A is out as an answer.