Noble gases' outer shells are already filled with 8 electrons (other than He, which has 2, but is still filled and stable). Atoms bond with other elements to fill their outer shell, but they don't need to do that and are already stable.
Anomalous data on a graph would show up as say a very high or very low value which does not fit in with the normal values which may be background values.If it was a straight line graph then the anomalous point would plot well above or below the line or if it was a bar graph ie a histogram it would be much higher or lower than the surrounding data. In mineral exploration, anomalies are looked for in say geophysics or geochemistry data values for high or low magnetism or conductivity or high chemical values indicating the presence of valuable minerals at that point.
Answer : The number of moles of oxygen needed are, 1.5 moles.
Explanation :
The balanced chemical reaction will be:
Now we have to calculate the moles of oxygen.
From the balanced chemical reaction we conclude that,
As, 6 moles of water vapor produces from 5 moles of oxygen
So, 1.80 moles of water vapor produces from 
moles of oxygen
Therefore, the number of moles of oxygen needed are, 1.5 moles.
Formula mass, molar mass and Avagadro's number.
Explanation:
number of atoms in a compound can be calculated by knowing the molar mass of the compound or element, the result will be multiplied by avagadro's number (6.022*10^23)
1 mole of a substance is equal to Avagadro number of atoms.
If the number of moles is known of a compound or element its molar mass can be calculated as:
n= Weight of the compound/element given/ molecular weight of the same.
formula mass is the mass of compound ie chemical compound formed with different molecules. its mass is calculated by adding the molar masses of all the elements taking part in its assembly.
