Answer:
Fe³⁺ and Mn⁺²
B⁻ and C
Explanation:
Isoelectronic are species that have the same number of electrons. A neutral species has the same number of protons and electrons, and the number of protons in the atomic number (Z) found in the periodic table.
A cation (positive ions) lost the numbe of electrons indicate in its charge, and an anion (negative ions) gain the number of electrons indicate in its charge. So, let's identify the number of electrons (e-) in each one the atoms:
First column:
Zn: Z = 30, e- = 30
Fe³⁺: Z = 26, e- = 26 - 3 = 23
Mn⁺²: Z = 25, e- = 25 - 2 = 23
Ar: Z = 18
Isoelectronic: Fe³⁺ and Mn⁺²
Second column:
Ge⁺²: Z = 32, e- = 32-2 = 30
Cl⁻: Z = 17, e- = 17 + 1 = 18
B⁻: Z = 5, e- = 5 + 1 = 6
C: Z = 6, e- = 6
Isoelectronic B⁻ and C