Yes they can have origins in nature. A bunch of the elements on the periodic table are chemicals and this are basic substances and cannot be man made.
ITS A SIMPLE.............................
FuFu Boys
Answer:
0.92 kg
Explanation:
The volume occupied by the air is:

The moles of air are:

The heat required to heat the air by 10.0 °C (or 10.0 K) is:

Methane's heat of combustion is 55.5 MJ/kg. The mass of methane required to heat the air is:

An atom is the smallest particle that can have the properties of a compound.