Final answer:
The highest possible oxidation states of the first half of the first transition series elements are achieved by losing all valence s and d electrons, with titanium reaching +4, and iron displaying a range from 2+ to 6+. These states are not always the most stable forms, with typical oxidation states from 2+ to 7+ for these metals.
Step-by-step explanation:
To determine the highest possible oxidation state for elements in the first half of the first transition series, you need to consider the electronic configuration of the atom. Loss of electrons from both the s and d orbitals of their valence shells will attain their highest possible oxidation states. Taking titanium as an example, titanium (IV) is formed when a titanium atom loses its two 3d and two 4s electrons, resulting in a +4 oxidation state.
However, as we continue through the series, not all valence electrons can be removed due to increasing pairing energy. Iron is known to form oxidation states from 2+ to 6+, with iron(II) and iron(III) being most common. These higher oxidation states are not always the most stable form for some elements. For example, metals from scandium to manganese can lose all of their valence s and d electrons to achieve oxidation states ranging typically from 2+ to 7+.