It is because in that time science was not established. This is, the experimentation to test hypotheses, which is a fundamental part of the scientific method, was not applied.
Atoms can not be seen, then they could only reflect or philosophize on this matter. This method is not able to give good answers to so complicated scientific matters.
Given:
Mass, m = 51.1 g
Volume, V = 6.63 cm³
By definition,
Density = Mass/Volume
= (51.1 g)/(6.63 cm³)
= 7.7074 g/cm³
In SI units,
Density = (7.7074 g/cm³)*(10⁻³ kg/g)*(10² cm/m)³
= 7707.4 kg/m³
Answer: 7.707 g/cm³ or 7707.4 kg/m³
A. would not help and maybe make it harder to get accurate measurements.
b. would make more delta T which will improve its accuracy
c. will also increase delta T.
Answer : The volume of 
gas needed are, 90 L
Explanation : Given,
Volume of 
= 60 L
Now we have to determine the volume of needed.
As we know that at STP, 1 mole of gas contains 22.4 L volume of gas.
The given balanced chemical reaction is:
By the stoichiometry we can say that, 2 moles of react with 3 moles of oxygen gas to give 2 moles of 
gas and 2 moles of water vapor.
From the balanced reaction we conclude that,
As, 
volume of react with 
volume of gas
So, 
volume of react with 
volume of gas
Thus, the volume of gas needed are, 90 L
