Answer for your question is;
2,6 = 8
The first shell is 2 electrons the other shell is 6 electrons
The specific heat capacity the substance is calculated using the below formula
Q(heat) = Mc delta T
Q =1560 cal
m(mass) 312 g
delta T (change in temperature ) = 15 c
C= specific heat capacity=?
by making c the subject of the formula
c=Q/m delta T
= 1560 cal/ 312g x 15 c = 0.33 cal/g/c (answer B)
The answer is C a combustion’s reaction