Question

Examine the following set of ionization energy values for a certain element. How many valence electrons does an atom of the neutral element possess?

IONIZATION STEP IONIZATION ENERGY (kJ/mol)

Eil 1012

Ei2 1903

Ei3 2912

Ei4 4956

Ei5 6273

Ei6 22233

Ei7 25997

Enter your answer numerically as an integer.

Answer 1

the valence electrons in this certain element = 5

Eil 1012 < Ei2 1903 < Ei3 2912 < Ei4 4956 < Ei5 6273 < Ei6 22233 < Ei7 25997

here we are observing the ionization energy values (Ei) . for first 5 energy values are slightly increase to one by one.

for coming to 6 ionization energy value is drastically increase.

so this indicates , the enrgy required to remove first 5 electrons is less compared to eneergy required to remove

6 electron.so first 5 electrons are easily removed.

so the valence electrons in this certain element = 5

the electron configuration of 5 valence electrons = [Ne]ns2np3

if the certain element lose 5 electrons , then it gets stable noble gas configuration. so more energy is required to remove electron from stable gas.