Final answer:
The total number of valence electrons in NH₄⁺ ion is 8, which is calculated by adding 5 valence electrons from nitrogen and 4 from the hydrogen atoms (one for each) and then subtracting 1 electron due to the ion's positive charge.
Step-by-step explanation:
The student asked about the total number of valence electrons in the ion NH4+. To determine this, we consider the electrons contributed by the nitrogen atom and the hydrogen atoms. A neutral nitrogen atom has 5 valence electrons because it is in group 15 of the periodic table. Each hydrogen atom contributes 1 valence electron, and since there are four hydrogen atoms, that adds up to 4 valence electrons. Adding these together gives us (5 + 4) 9 valence electrons for the NH4 molecule. However, since we are dealing with the positively charged ion NH4+, we must subtract one electron due to the positive charge. Thus, the total number of valence electrons in the NH4+ ion is 8.