Final answer:
Removing an electron from the outer shell of an atom changes its chemical properties by creating a cation that is more reactive and likely to form new types of chemical bonds to stabilize its electron configuration.
Step-by-step explanation:
The chemical properties of an element are largely determined by the electrons in its valence shell, which is the outermost electron shell of the atom. When an electron is removed from this shell, the atom becomes an ion with a positive charge, known as a cation. This ionization changes the reactivity of the element.
For instance, an atom with a filled valence shell, like those in Group 18 of the periodic table, is typically unreactive or inert. However, if an electron is removed and the shell is no longer filled, the atom would become more reactive, as it seeks to stabilize by filling the valence shell again, either through ionic or covalent bonding.
Compounds formed by elements are influenced by the ionization energy, which is the energy needed to remove an electron from an atom. This ionization energy generally increases from the lower left of the periodic table to the upper right, with noble gases having very high ionization energies due to their full valence shells. When an outer shell electron is removed, the resulting cation may have different chemical bonds and reactivity than the neutral atom. The new electron configuration also often results in oxidation states that impact the types of compounds the element can form.