Because metals that are more reactive than carbon wont react with it.
The
Earth is composed of four different layers. Many geologists believe
that as the Earth cooled the heavier, denser materials sank to the
center and the lighter materials rose to the top. Because of this, the
crust is made of the lightest materials (rock- basalts and granites) and
the core consists of heavy metals (nickel and iron).
<span>The crust is the layer that you live on, and it is the most widely studied and understood. The mantle
is much hotter and has the ability to flow. The Outer and Inner Cores
are hotter still with pressures so great that you would be squeezed into
a ball smaller than a marble if you were able to go to the center of
the Earth!!!!!!</span>
Butane is C₄H₁₀.

The balanced equation is 2 C₄H₁₀ + 13 O₂ <span>→</span> 8 CO₂ + 10 H₂O.
Doesnt the number of carbon atoms stay the same.
Though the weight of carbon in 1.5g is 1.24g.
This is because the RAM of C4 is 48.
The RFM of C4H10 is 58. Therefore, 48/58 is carbon in butane.
48/58 x 1.5 = 1.24g
I uploaded the answer to a file hosting. Here's link:
tinyurl.com/wpazsebu