pairs of ions having same electronic configuration isa) cr3, Fet3b) Fet3, Mn+2c) Fe*, Co*3d) Sc3, Fet3

The electronic configuration of ions is determined by the number of electrons. In a neutral atom, the number of electrons is equal to the number of protons. When an atom loses or gains electrons, it becomes an ion and its electronic configuration changes.

a) Cr3+ and Fe3+ Chromium (Cr) has an atomic number of 24, so it has 24 electrons in its neutral state. When it loses 3 electrons to become Cr3+, it has 21 electrons. Iron (Fe) has an atomic number of 26, so it has 26 electrons in its neutral state. When it loses 3 electrons to become Fe3+, it has 23 electrons. Therefore, Cr3+ and Fe3+ do not have the same electronic configuration.

b) Fe3+ and Mn2+ As mentioned above, Fe3+ has 23 electrons. Manganese (Mn) has an atomic number of 25, so it has 25 electrons in its neutral state. When it loses 2 electrons to become Mn2+, it has 23 electrons. Therefore, Fe3+ and Mn2+ have the same electronic configuration.

c) Fe* and Co3 The asterisk () usually denotes an excited state, but without more information, it's not possible to determine the electronic configuration of these ions.

d) Sc3+ and Fe3+ Scandium (Sc) has an atomic number of 21, so it has 21 electrons in its neutral state. When it loses 3 electrons to become Sc3+, it has 18 electrons. As mentioned above, Fe3+ has 23 electrons. Therefore, Sc3+ and Fe3+ do not have the same electronic configuration.

So, the pair of ions having the same electronic configuration is Fe3+ and Mn2+.