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.
Sunlight is collected from a renewable resource, which is naturally replenished one a human timescale
This is a incomplete question. The complete question is:
It takes 348 kJ/mol to break a carbon-carbon single bond. Calculate the maximum wavelength of light for which a carbon-carbon single bond could be broken by absorbing a single photon. Round your answer to correct number of significant digits
Answer: 344 nm
Explanation:
E= energy = 348kJ= 348000 J (1kJ=1000J)
N = avogadro's number = 
h = Planck's constant = 
c = speed of light = 

Thus the maximum wavelength of light for which a carbon-carbon single bond could be broken by absorbing a single photon is 344 nm
Answer:
proposing a hypothesis.
Explanation: Therefore the last step in the scientific method is proposing a hypothesis or obtaining a conclusion.
Answer:
3.75 g.
Explanation:
<em>mass percent is the ratio of the mass of the solute to the mass of the solution multiplied by 100.</em>
<em />
<em>mass % = (mass of solute/mass of solution) x 100.</em>
<em></em>
mass of calcium nitrite = ??? g,
mass of the solution = 25.0 g.
∴ mass % = (mass of solute/mass of solution) x 100
<em></em>
<em>∴ mass of solute (calcium nitrite) = (mass %)(mass of solution)/100</em> = (15.0 %)(25.0 g)/100 = <em>3.75 g.</em>