Which of the following are isoelectronic and iso-structural NO−3, CO2−3, CIO−3, SO3?

Q. Which of the following are isoelectronic and iso-structural NO−3, CO2−3, CIO−3, SO3?

1. NO⁻₃,CO²⁻₃
2. SO3, NO−3
3. CIO⁻₃, CO²⁻₃

Answer: NO⁻₃,CO²⁻₃