Order the following elements from least to greatest ionization energy. f, s, k, caa
a. f < s < k < cab)
b. k < ca < s < fc
c. s < f < ca < kd
d. k < ca < f < s

Option B

Explanation:

Given elements are F, S, Ca, K

Assuming that the order of ionization energies is asked for first ionization energy

Ionization energy is defined as the minimum energy required to remove an electron from its valence shell

Among these elements K will have least ionization energy because it requires minimum energy to remove an electron form its outer most shell as after removing the valence electron it will gain octet configuration, therefore it wants to loose that valence electron

Among the given elements F has maximum ionization energy because of its small size and high nuclear charge and due to this maximum amount of energy is required to remove the valence electron

While comparing between Ca and S, S has maximum ionization energy because of its small size and high nuclear charge

∴ Order is K < Ca < S < F

it is b that is the answer.