C) Noble gases
The six noble gases are helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe), and radon (Rn). Their atomic numbers are, respectively, 2, 10, 18, 36, 54, and 86.
Answer : The molecular formula of the compound is, 
Explanation :
Molecular formula : It is the representation of substance by the symbols and it denotes the number of atoms of each element present in the compound.
Now count the number of carbon, hydrogen, nitrogen and oxygen atoms present in the given compound.
As we see that in the given compound, there are 8 atoms of carbon element, 3 atoms of oxygen element, 1 atom of nitrogen element, 9 atoms of hydrogen element.
Thus, the molecular formula of the compound will be 
Answer:
53 meters = 53000 millimeters
Explanation:
In this question we have to convert meters into millimeters .
By metric conversion,
Since, 1 meter = 1000 mm
Therefore, 53 meters = 53 × 1000
= 53000 millimeters
53 meters = 53000 millimeters is the answer.
Carbon-12 has the following electron configuration: 1s2-2s2-2p2. As seen in the configuration, the right answer is: the first electron shell has 4 orbitals.