Answer:
C. 14
Explanation:
The mass number is the number of protons + neutrons and the atomic number is the number of protons.
If the mass number is 27, you subtract the atomic number, 13.
27 - 13 = 14 neutrons
NO + O2 -> NO2
it is balanced
50,662.5 kPa
Ok so the answer for 9 is
x/6=4
x=24
Solve for x by simplifying both sides of the equation, then isolating the variable.