Ionization energies

Authors Avatar

INTRODUCTION:

The ionization energy of an atom measures how strongly an atom holds its electrons.The ionization energy is the minimum energy required to remove an electron from the ground state of the remote gaseous atom

The first ionization energy, I1, is the energy needed to remove the first electron from the atom: i.e. the most loosely held electron!

Na(g) -> Na+(g) + 1e-

The second ionization energy, I2, is the energy needed to remove the next (i.e. the second) electron from the atom

Na+(g) -> Na2+(g) + 1e-

The higher the value of the ionization energy, the more difficult it is to remove the electron

Join now!

As electrons are removed, the positive charge from the nucleus remains unchanged, however, there is less repulsion between the remaining electrons

 INVESTIGATION: Periodic trends in ionization energies

First ionization energies as a function of atomic number

  • 1.Within each period (row) the ionization energy typically increases with atomic number
  • 2.Within each group (column) the ionization energy typically decreases with increasing atomic number

HYPOTHESIS:

  • Investigation 1: As the effective charge increases, or as the distance of the electron from the nucleus decreases, the greater the attraction between the nucleus and the electron. The effective ...

This is a preview of the whole essay

Here's what a star student thought of this essay

Avatar

Punctuation, grammar and spelling all to a good level. The format of the essay is well set out with clear graphs.

The candidate starts with a good definition of what an ionisation energy is. They give correct definitions of the different states of ionisation energy and good equations with state symbols. The definitions could be slightly better in chemical technical detail. The hypothesis are correct but the candidate should back them up with scientific theories and should link how ionisation energies relates to their investigation. The candidate does not account for the anomalies in the trends seen in the experiment which should be accounted for. The conclusions for each are adequate but the trends should be explained in more detail when they don't follow the general pattern.

The candidate responds well to the question investigating a topic that is normally beyond GCSE level. The only problem is lack of scientific detail between explaining some of the trends seen in the graphs