The process where fossil fuels, forests, or other carbon-containing substances are burned, addin more carbon dioxide to the air is the combustion.
Some examples of combustion are:
Fossil fuel:
Carbon + O2
C + O2 -> CO2
Forests (wood)
Wood = cellulose = [C6H10O5]n
[C6H10O5]n + 6nO2 = 6n CO2 + 5n H2O
So, in general the combustion of organic matter produces CO2 and water.
Adding an atom will increase the repulsion between existing atoms and lone pairs. Added atom will result in bond pair-bond pair and bond pair-lone pair repulsion. The magnitude of the lone pair-bond pair repulsion is greater than the bond pair-bond pair repulsion. The added atom will change the electron geometry and bring about a distortion in the molecular geometry.
4 is correct for this one
they can find dna at the crime scene wich will lead them to the guilty party