To determine which predictions can most likely be made about antimony (Sb) and iodine (I) based on their atomic characteristics, let us analyze the given properties step-by-step:
1. Atomic Radius:
- Sb: 145 pm
- I: 140 pm
Since antimony (Sb) has a larger atomic radius than iodine (I), we can infer that Sb's outer electrons are further away from the nucleus compared to I's outer electrons.
2. First Ionization Energy:
- Sb: Not given directly
- I: 1008 kJ/mol
Ionization energy is the energy required to remove one mole of electrons from one mole of atoms in the gaseous state. Elements with larger atomic radii generally have lower ionization energies because their outer electrons are less strongly attracted to the nucleus.
Given that Sb has a larger atomic radius than I, we can predict that Sb has a lower ionization energy compared to I.
3. Electron Affinity:
- Sb: -103 kJ/mol
- I: -295 kJ/mol
Electron affinity is the energy change that occurs when an electron is added to a neutral atom to form a negative ion. A more negative value indicates a higher tendency to gain an electron.
According to the given data, iodine (I) has a more negative electron affinity than antimony (Sb), meaning I has a higher tendency to gain an electron compared to Sb.
4. Electronegativity:
- Sb: 2.05
- I: Not given directly
Electronegativity is the tendency of an atom to attract electrons towards itself in a chemical bond. While we do not have the exact value for iodine (I), we know that in general, elements with smaller atomic radii and higher ionization energies tend to have higher electronegativity.
Given that iodine (I) has a smaller atomic radius and higher ionization energy compared to antimony (Sb), we can predict that I has a higher electronegativity compared to Sb.
Based on these analyses:
- Prediction:
- Sb has a lower ionization energy but a higher electronegativity than I: False. Sb should have a lower ionization energy and lower electronegativity.
- Sb has a higher ionization energy but a lower electronegativity than I: False. Sb should have a lower ionization energy.
- Sb has a lower ionization energy and a lower electronegativity than I: True. This prediction aligns with our prior deductions on both counts.
- Sb has a higher ionization energy and a higher electronegativity than I: False. Sb should have a lower ionization energy and lower electronegativity.
Therefore, the most accurate prediction is:
Sb has a lower ionization energy and a lower electronegativity than I.
