In which compound does Cr exhibit greater nonmetalic behavior, CrF2 or CrF6. Explain
In the compound CrF2, chromium (Cr) exhibits greater nonmetallic behavior compared to CrF6.
CrF2 is a binary compound, consisting of one chromium atom bonded to two fluorine atoms. In this compound, chromium has a +2 oxidation state, which means it has lost two electrons. This electron loss leaves chromium with a high effective nuclear charge, resulting in a higher attraction between electrons and the nucleus. As a result, chromium tends to have a higher electronegativity and behaves more like a nonmetal.
On the other hand, CrF6 is a compound called chromium hexafluoride, consisting of one chromium atom bonded to six fluorine atoms. In this compound, chromium has a +6 oxidation state, meaning it has lost six electrons. This electron loss makes chromium highly positively charged, resulting in a very high effective nuclear charge. In this state, the attractive force between electrons and the nucleus is very strong, making it difficult for chromium to attract and share additional electrons. As a result, the metallic behavior of chromium becomes more dominant.
Therefore, in CrF2, where chromium has a +2 oxidation state, it exhibits greater nonmetallic behavior compared to CrF6, where chromium has a +6 oxidation state.
To determine which compound, CrF2 or CrF6, exhibits greater nonmetallic behavior, we need to compare the oxidation state of chromium (Cr) and the electronegativity of fluorine (F) in each compound.
In CrF2, the oxidation state of Cr is +2, and it forms two bonds with fluorine. On the other hand, in CrF6, the oxidation state of Cr is +6, and it forms six bonds with fluorine.
The electronegativity of F is higher than that of Cr since fluorine is a nonmetal, while chromium is a transition metal. Electronegativity is a measure of an atom's ability to attract electrons towards itself in a chemical bond.
Considering these factors, we can say that CrF6 exhibits greater nonmetallic behavior compared to CrF2. This is because Cr in CrF6 has a higher oxidation state (+6) and forms more bonds with F (six bonds), indicating that it is more willing to accept and share electrons. As a result, CrF6 displays stronger nonmetallic characteristics.