Im guessing and i think the answer is yes.
Format Method - Writing the symbol of the cation and then the anion. Add whatever subscripts in order to balance the charges.
Crisscross Method - The numerical value of the charge of each ion is crossed over and becomes the subscripts for the other ion.
Answer:
the reaction is spontaneous at T > 2900 K
Explanation:
∴ ΔH = +120 KJ
∴ ΔS = (-42 J/K)*(KJ/1000 J) = -0.042 KJ/K
∴ ΔG < 0 ⇒ the reaction is spontaneous
⇒ at T = 2900 K:
⇒ ΔG = 120 - (2900)(-0.042) = 120 - 121.8 = - 1.8 KJ < 0
I think it would be D. atoms because they are very tiny but still take up space