5.58 X 
Litres is the volume, in liters, occupied by 0.015 molecules of oxygen at STP.
Explanation:
Data given:
molecules of oxygen = 0.015
number of moles of oxygen =?
temperature at STP = 273 K
Pressure at STP = 1 atm
volume = ?
R (gas constant) = 0.08201 L atm/mole K
to convert molecules to moles,
number of moles = 
number of moles = 2.49 x 
Applying the ideal gas law since the oxygen is at STP,
PV = nRT
rearranging the equation:
V = 
putting the values in the rearranged equation:
V = 
V = 5.58 X Litres.
A biomass source is an natural material.
The sun is natural.
Manure is natural.
Wood Chips are natural.
Paper is natural and treated with unnatural substances.
Think, does a chemical reaction take place? Do the rocks and/or the water undergo any chemical changes?
It's an example of a molecule
Bohrs model says that electrons move in fixed shells (which have fixed distances) around the nucleus of an atom.
