Answer:
D. because water and mud behaved in a similar way in the past as they do today
Explanation:
One of the fundamental theories in the field of earth science is the theory of uniformitarianism.
Uniformitarianism was proposed by James Hutton in the 18th century in Scotland. The theory states that "geologic processes occurring today have occurred in times past and that the present is the key to past".
The simple meaning of the theory is that, the processes on earth today such as weathering, erosion, e.t.c have also occurred in times past. Those processes still occur today and an understanding of such events today will help us have a better insight into the past.
Therefore, ripple marks just as they form today from action of mud and water would be formed in a similar way in the past.
Molar mass of C: 12.011 g/mol
The equation says C20, which means there are 20 carbon atoms in each molecule of Vitamin A. So, we multiply 12.011 by 20 to get 240.22 g/mol carbon.
Molar mass of H: 1.0079 g/mol
The equation says C30, which means there are 30 hydrogen atoms in each molecule of Vitamin A. So, we multiply 1.0079 by 30 to get 30.237 g/mol hydrogen.
Molar mass of O: 15.999 g/mol
The equation says O without a number, which means there is only one oxygen atom in each molecule of Vitamin A. So, we leave O at 15.999 g/mol.
Then, just add it up:
240.22 g/mol C + 30.237 g/mol H + 15.999 g/mol O = 286.456 g/mol C20H30O
So, the molar mass of Vitamin A, C20H30O, is approximately 286.5 g/mol.
Answer : The volume of oxygen at STP is 112.0665 L
Solution : Given,
The number of moles of 
= 5 moles
At STP, the temperature is 273 K and pressure is 1 atm.
Using ideal gas law equation :
where,
P = pressure of gas
V = volume of gas
n = the number of moles
T = temperature of gas
R = gas constant = 0.0821 L atm/mole K (Given)
By rearranging the above ideal gas law equation, we get
Now put all the given values in this expression, we get the value of volume.
Therefore, the volume of oxygen at STP is 112.0665 L
