Electronic configuration of Rb: 2.8.8.8.8.3
Valence electron is 3....
By Using relative and radiometric dating methods hope this helps!!
There are several information's already given in the question. Based on those information's the answer can be easily determined.
M = <span>1.11 g CH4
C = </span>4.319 kJ g C⋅°
∆T = 35.65 - 24.85 degree centigrade
= 10.8 degree centigrade.
Then
∆H =−M ⋅ C ⋅∆T
= - 1.11 * 4.319 * 10.8
= - 51.776 kJ/<span>mol
I hope the procedure is clear enough for you to understand.</span>