Is my answer correct?
Can someone explain how to get the right net ionic equation

Option D.

2Ag⁺(aq) + Ni(s) —> 2Ag(s) + Ni²⁺(aq)

Explanation:

From the question given above:

Ni(s) —> Ni²⁺(aq) + 2e¯

Ag⁺(aq) + e¯ —> Ag(s)

We can obtain the net ionic equation by combining both equation as shown below:

Ag⁺(aq) + e¯ + Ni(s) —> Ag(s) + Ni²⁺(aq) + 2e¯

Next, we shall balance the equation. This can be obtained as follow:

Ag⁺(aq) + e¯ + Ni(s) —> Ag(s) + Ni²⁺(aq) + 2e¯

There are 2 atoms of e¯ on the right side and 1 atom on the left side. It can be balance by putting 2 in front of e¯ as shown below:

Ag⁺(aq) + 2e¯ + Ni(s) —> Ag(s) + Ni²⁺(aq) + 2e¯

Next, we shall balance the charge on both sides. This is illustrated below:

TOTAL charge on the left = +1 + (–2)

= 1 – 2

= –1

TOTAL charge on the right side = +2 + (–2)

= 2 – 2

= 0

Thus, to balance the charge, put 2 in front of Ag⁺ as shown below:

2Ag⁺(aq) + 2e¯ + Ni(s) —> Ag(s) + Ni²⁺(aq) + 2e¯

There are 2 atoms of Ag on the left side and 1 atom on the right side. It can be balance by putting 2 in front of Ag as shown below:

2Ag⁺(aq) + 2e¯ + Ni(s) —> 2Ag(s) + Ni²⁺(aq) + 2e¯

Next, cancel out 2e¯ from both side to obtain the net ionic equation. Thus, we have:

2Ag⁺(aq) + Ni(s) —> 2Ag(s) + Ni²⁺(aq)

assuming that your periodic table has eighteen columns, you should highlight   the four elements in the third column from the left of the table.

neutral atoms of elements after calcium contain d electrons. the energy of d orbitals of a particular main shell lies between the energy of the s and p orbitals of the next main shell. for example, electrons in the have energy higher than those in the orbital while lower than those of the orbital.

by the aufbau principle, electrons fill orbitals one at a time, starting from those of the lowest energy. the orbital is therefore filled right after orbitals and before orbitals.  

potassium has electron configuration and calcium . the s orbital of a main shell holds a maximum of two electrons. the next element would thus have the electron configuration and satisfy the requirements.

a neutral atom of the element contains three electrons on top of the most recent noble gas element. it should thus be placed in the third column of the periodic table. both scandium and yttrium would satisfy the conditions. an aufbau diagram indicates that the 4f orbital is filled before the 5d. however, it appears that exceptions exists for both lanthanum and actinium. neutral atoms of the two d-block elements also demonstrate the and should be highlighted as well.