How many single covalent bonds could an element with the electron configuration 1s2 2s2 2p5 form?
A-2
B-3
C-1
D-4

1

Explanation:

I would say 1 because that configuration has 7 valence electrons.  The goal of the atom is to gain a full octet so it just needs to gain 1 more electron to get the full octet.  To get the one electron to fill the valence shell it would only need to have 1 covalent bond.

I hope this helps.  Let me know if anything is unclear.

answer : a model is often used to explain and make things easier to understand when any scientific topic needs to be demonstrated and explained.

as in this case where a scientist wants to use a model to present the results of his detailed scientific investigation. he should do it as it will him to make the audience understand the concept in a much better way. also, it can be changed according to new scientific understandings.

the ratio of the conjugate base to the acid required to attain the desired ph.