So, you need to have same ammount of atoms on the left and on the right side of the equation. You need to count the ammount of attoms of every substance on the left, and make sure that on the right side the ammount is same. For example in the 1st one it’s 6Sn+2P4=2Sn3P4, so that you have 6atoms of Sn on the left and 6 atoms of Sn on the right, same with the P
I believe that the answer is 1.8^24 of Ni atoms in 3.6 mol of Ni.
Hope this helps. :)
Answer:
The answer is b. The number of collisions of gas particles increases