You can tell if each side of the equation has the same molar mass.
Add an alkaline compound to raise the pH to 7.2.
Answer: [Kr] 5s1 4d10 silver
[Xe] 6s2 4f14 5d7 Iridium
[Ar] 4s2 3d10 4p4 selenium
[Kr] 5s1 4d4 niobium
[Xe] 6s1 4f14 5d10 gold
[Kr] 5s2 4d10 5p4 tellurium
Explanation:
Selenium and tellurium will have the same properties because they both belong to group 16 in the periodic table.
Silver and gold will have the same properties because they both belong the group 11 in the periodic table.
Elements having the same outermost shell configuration show similar properties since chemical reactions occur by loss or gain of electrons. This loss or gain is determined by the number of electrons occupying the outermost shell. Elements in the same group have the same outermost shell electron configuration and similar properties.
