The way an experiment is carried is out is determined by the purpose of that experiment.
Answer:

Explanation:
The atomic weight of oxygen = 15.9994 g
This mass corresponds to 1 mole of the oxygen atoms.
Thus,
15.9994 g mass of oxygen contains
atoms of oxygen.
1.4 kg = 1400 g ( 1 kg = 1000 g)
So,
1400 g mass of oxygen contains
atoms of oxygen.
Number of atoms in 1400 g of oxygen = 
Also, 1 atom of oxygen contains 8 protons
Charge of 1 proton = + 
So, Charge on 1 atom of oxygen = 
Thus,
Charge on
atoms of oxygen = 
Thus, positive charge in 1.4 kg of oxygen = 
Krafla Volcano in Iceland,
Here we have to compare the state of helium gas at STP and high temperature and low pressure.
At STP (standard condition of temperature and pressure) i.e. 273K temperature and 1 bar pressure. At STP helium gas will behave as a real gas.
At higher temperature and low pressure Helium will behave as an ideal gas.
The ideal gas conditions are developed on taking into account two factors: (i) the gas molecules are point of mass and having no volume. (ii) there is no existence of force of attraction between the molecules.
The deviation from ideal gas to the real gas depends upon the van der waals' interaction between the gas molecules. Now in low pressure and high temperature, we can ignore the volume and also the inter-molecular force of attraction. Thus the gas sample can behaved as ideal gas.
But at elevated pressure and low temperature i.e. STP the assumptions are not valid and it will behave as real gas.
Answer: 94.07%
Explanation:
Percentage yield can be calculated by the formula
%yield = Experimental yield/Theoretical yield x100
Experimental yield = 7.93g
Theoretical yield = 8.43
%yield = Experimental yield/Theoretical yield x100
%yield = 7.93/8.43 x 100 = 94.07%