Asection of the periodic table is shown below: a portion of two rows of the periodic table is shown. the first row reads two helium 4.003. the second row reads seven nitrogen 14.007, eight oxygen 15.999, nine flourine 18.998, and 10 neon 20.180. helium and neon form the last column of the periodic table. which of the following statements is true? neon is more reactive than fluorine because neon needs only one electron to fill its outermost shell. neon is more reactive than oxygen because neon has to lose only one electron to fill its outermost shell. fluorine is more reactive than nitrogen because fluorine needs only one electron to fill its outermost shell. fluorine is more reactive than neon because fluorine has to lose only one electron to fill its outermost shell.

 The statement  which is true  is

Fluorine  is more reactive  than nitrogen because fluorine  needs  only  one electron to fill  its  outermost  shell.

     Explanation

Fluorine  has  electron configuration  of 1S²2S²2P⁵  while nitrogen  has 1S²2S²2P³  electron configuration.

The 2P sub shell  for nitrogen   is  half filled  therefore it is sable  than fluorine.

since  p orbital  can hold a maximum  of  6  electrons ,Fluorine  requires  1 electron  to  completely fill  it's 2P  sub shell  which make it    more  reactive than nitrogen.

answer: the enthalpy of the overall chemical reaction is +87.88 kj or +88 kj.

according to hess's law, the overall enthalpy of a reaction is the difference between the sum of enthalpy values of all the products and the sum of enthalpy values of all the reactants.

δh(reaction) = ∑nδh(products) - ∑nδh(reactants)

δh(reaction) = [δh +δh] - [δh]

δh(reaction) = [1(-287.02) + 1(0) ] - [1(-374.9)] kj = +87.88 kj

here, δh (pcl3) = -287.02 kj, δh(cl2) = 0, δh(pcl5) = -374.9 kj

therefore, enthalpy of the overall reaction is +87.88 kj or +88 kj.

"the periodic table is arranged in order of atomic number."