Hydrogen reacts with an element to form a compound. which element would have the most electrons available to react with hydrogen?

a. oxygen
b. chlorine
c. neon
d. nitrogen

            Chlorine

                        As we know the only electrons which take part in chemical bonding are the valence electrons. Therefore, in given options we will look for an atom having greater umber of valence electron. In order to find the number of valence electrons we will draw the electronic configuration of each element and will find the number of electrons in valence shell.

Oxygen:

                                          8  =  1s², 2s², 2p⁴

There are 6 electrons in valence shell (i.e. 2) of Oxygen.

Chlorine:

                                  17  =  1s², 2s², 2p⁶, 3s², 3p⁵

There are 7 electrons in valence shell (i.e. 3) of Chlorine.

Neon:

                                             10  =  1s², 2s², 2p⁶

There are 8 electrons in valence shell (i.e. 2) of Neon but it will not react with Hydrogen because of its stability and complete octet.

Nitrogen:

                                               7  =  1s², 2s², 2p³

There are 5 electrons in valence shell (i.e. 2) of Nitrogen.

                   Except Neon, all three atoms will react with \hydrogen and among these three Chlorine has the greatest number of valence electrons and hence, it is the correct answer.