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.

the density(ratio between mass and volume as m/v) decreases from top to bottom in periodic table group as the size increases and nuclear charge decreases. but in periods density increases from left to right as atom size decreases and nuclear charge increases.

you did not give any options thus this is the best answer i can give to you with this little information you have given

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