D. I or Iodine
This is because they are both in the same periodic family (the halogens) and thus the number of valence electrons are the same
<span> 1C3H8(g) + 5 O2(g) → 3 CO2(g) + 4 H2O, the ∆H is –2200 kJ
1mol </span>C3H8(g) ---- –2200 kJ
2mol C3H8(g) ----2(–2200 kJ)=-4400kJ
<span>Most of earths carbon is in the atmosphere in the form of a gas?</span>
