Final answer:
The radius of the oxide ion is 168 pm. Therefore, the correct answer is a. 176 pm.
Step-by-step explanation:
To determine the radius of the oxide ion, we need to consider the edge length of the unit cell of alpha polonium (Po) and its atomic radius. Given that the edge length of the unit cell is 336 pm, we can calculate the radius of Po using the formula r = 1/2 * edge length = 168 pm.
The oxide ion (O²⁻) is formed by gaining two electrons compared to a neutral oxygen atom. Since the radius of the oxide ion is the same as the radius of the oxygen atom, we can conclude that the radius of the oxide ion is also 168 pm.
The question provided is about finding the radius of the oxide ion, given the radius of the strontium ion (Sr2+) and the density of strontium oxide (SrO). This involves understanding of ionic radii and density concepts within chemistry.
If the radius of Sr2+ is 127 pm, the radius of the oxide ion cannot be directly obtained from that value alone without additional information such as the crystal structure of SrO or the specific arrangement of ions in the solid.
However, given the information typically found in a High School curriculum, and without additional data, it is not possible to calculate the radius of the oxide ion (O2-) based solely on the density of SrO and the radius of Sr2+. Therefore, the answer cannot be confidently provided under these constraints.