_is/are isoelectronic with K+:

Explanation

The correct option is d) All of these. Isoelectronic species are atoms or ions that have the same number of electrons. K+ is a potassium ion that has lost one electron, resulting in a configuration of 2, 8, 8. Let's analyze each option: a) P-3: Phosphorus (P) normally has 15 electrons. By gaining three electrons, it forms the P-3 ion, which has a configuration of 2, 8, 8, 2. This configuration is isoelectronic with K+ (2, 8, 8). b) Si-4: Silicon (Si) normally has 14 electrons. By gaining four electrons, it forms the Si-4 ion, which has a configuration of 2, 8, 8, 4. This configuration is isoelectronic with K+ (2, 8, 8). c) S-2: Sulfur (S) normally has 16 electrons. By gaining two electrons, it forms the S-2 ion, which has a configuration of 2, 8, 8, 6. This configuration is isoelectronic with K+ (2, 8, 8). Therefore, all three options (a, b, and c) are correct because P-3, Si-4, and S-2 are isoelectronic with K+. They all have the same number of electrons as K+ and share the same electron configuration of 2, 8, 8. So, the correct option is d) All of these.