Final answer:
The correct formula for manganese(II) nitrate is Mn(NO₃)2, as it combines the Mn2+ ion with two NO₃− ions to form a neutral compound.
Step-by-step explanation:
The formula for manganese(II) nitrate is Mn(NO₃)2. This compound is formed by combining manganese(II) ion, Mn2+, with the nitrate ion, NO₃−, in a 1:2 ratio because manganese has a +2 charge and the nitrate ion has a -1 charge. The correct formula represents this stoichiometric relationship, adhering to the principle of charge neutrality in ionic compounds. Thus, the correct option among the given choices is 1) Mn(NO₃)2.