This question is incomplete, the complete question is;
The area of the gold electrodes on the quartz crystal microbalance at the opening of Chapter 2 is 3.3 mm^2. One gold electrode is covered with DNA at a surface density of 1.2 pmol/cm2.
(a) How much mass of the nucleotide cytosine (C) is bound to the surface of the electrode when each bound DNA is elongated by one unit of C. The mass formula mass of the bound nucleotide is cytosine + deoxyribose + phosphate = C9H10N3O6P = 287.2 g/mol
Answer: mass of the nucleotide (c) bound is 11.37 g
Explanation:
Given that the area of gold electrodes = 3.3 mm^2
surface density of one gold electrode = 1.2 pmol/cm^2
that is to that in every 1 cm^2 of area, 1.2 pmol DNA is present
therefore
mass of nucleotide present in 3.3 mm^2 is;
= (1.2/100 * 3.3) pmol
= 0.0396 pmol
we were given that formula mass of the bound nucleotide = 287.2 g/mol
so
mass of the nucleotide (c) bound = ( 287.2 * 0.0396 )g
mass of the nucleotide (c) bound = 11.37 g
Answer : The number of molecules present in nitrogen gas are, 
Explanation :
First we have to calculate the moles of nitrogen gas by using ideal gas equation.
where,
P = Pressure of 
gas = 
(1 atm = 760 mmHg)
V = Volume of gas = 985 mL = 0.982 L (1 L = 1000 mL)
n = number of moles = ?
R = Gas constant = 
T = Temperature of gas = 
Now put all the given values in above equation, we get:
Now we have to calculate the number of molecules present in nitrogen gas.
As we know that 1 mole of substance contains 
number of molecules.
As, 1 mole of gas contains number of molecules
So, 
mole of gas contains 
number of molecules
Therefore, the number of molecules present in nitrogen gas are,
Note that
1 m = 3.2808 ft
Therefore
1 km = 3280.8 ft
and
Answer: 1.0682 x 10⁵ ft/hr
<span>Carbon must share 4 electrons total with the the two Oxygen atoms in order to fill it's outer electron shell, and each Oxygen atom must share 2 electrons with the Carbon atom to fill their electron shells. Therefore, in total 8 electrons must be shared (4+2+2=8)</span>
