Answer to Question #204761 in General Chemistry for Master j

Question

i. What is meant by first ionization energy?

ii. Using calcium as an example, write a balanced chemical equation to illustrate first ionization energy.

iii. State and explain the general variation in first ionization energy going from sodium to argon, across Period 3.

Answer 1

I. First ionization energy is the energy required to remove the most loosely held electron from one mole of neutral gaseous atoms to produce 1 mole of gaseous ions each with a charge of 1+

ii.Ca(g) + e– → Ca–(g).

iii.The major difference is the increasing number of protons in the nucleus as you go from sodium across to argon. That causes greater attraction between the nucleus and the electrons and so increases the ionisation energies. In fact the increasing nuclear charge also drags the outer electrons in closer to the nucleus.