Among the given species. \( \text{S}_2\text{O}_3^{2-} \) (thiosulfate ion) has a pyramidal geometry around the central sulfur atom due to the presence of a lone pair on sulfur, resulting in a trigonal pyramidal shape.\( \text{SO}_4^{2-} \) (sulfate ion) has a tetrahedral geometry due to its symmetrical distribution of oxygen atoms around the central sulfur atom.\( \text{SO}_3^{2-} \) (sulfite ion) also adopts a trigonal pyramidal structure around sulfur, but in this context, \( \text{S}_2\text{O}_3^{2-} \) is more relevant to pyramidal geometry.\( \text{S}_2\text{O}_7^{2-} \) (disulfate ion) has a tetrahedral arrangement with respect to its central atoms, making it non-pyramidal.
Therefore, only one species, \( \text{S}_2\text{O}_3^{2-} \), exhibits pyramidal geometry.
The correct increasing order for bond angles among \( \text{BF}_3, \, \text{PF}_3, \, \text{and} \, \text{CF}_3 \) is:
A body of mass 1000 kg is moving horizontally with a velocity of 6 m/s. If 200 kg extra mass is added, the final velocity (in m/s) is: