Question

determine the location of the elements on the periodic table with the smallest ionization energy.
i need a hint
the elements with a small ionization energy are all in group 18 (the column at the right of the periodic table).
the elements with a small ionization energy are all in period 7 (the row at the bottom of the periodic table).
the elements with a small ionization energy are all in group 1 (the column at the left of the periodic table).
the elements with a small ionization energy are all in period 1 (the row at the top of the periodic table).

Explanation:

Ionization energy is the energy required to remove an electron from an atom. In the periodic table, ionization energy generally decreases down a group and increases across a period. Group 1 elements (alkali metals) have only one valence electron. They can easily lose this electron to achieve a stable electron configuration. As we move down group 1, the atomic radius increases. The out - ermost electron is further from the nucleus and is less strongly attracted. So, group 1 elements have relatively low ionization energies compared to other groups.
Group 18 (noble gases) have very high ionization energies because they have a full valence shell and are very stable. Period 1 has only two elements (H and He). He is a noble gas (high ionization energy) and H has a relatively higher ionization energy compared to group 1 metals. Period 7 has some very heavy elements, but their ionization energies are not the lowest overall as the trend within groups (especially group 1) dominates for the lowest ionization energy.

Answer:

The elements with a small ionization energy are all in group 1 (the column at the left of the periodic table).