Answer is: orbitals are regions of the most probable location of electrons.
Each orbital in an atom is characterized by a unique set of values of the three quantum numbers n, l, and ml.
Magnetic quantum number (ml) specifies the orientation in space of an orbital of a given energy and shape . Magnetic quantum number divides the subshell into individual orbitals which hold the electrons, there are 2l+1 orbitals in each subshell. For example, p orbitals (and their electrons) have three orientations in spase (px, py and pz).
Principal quantum number (n) describes the size of the orbital. There are one s orbital (angular quantum number l=0), three p orbitals (angular quantum number l=1 and magnetic quantum number ml = -1,0,+1) and five d orbitals (angular quantum number l=2 and magnetic quantum number ml = -2,-1,0,+1,+2).
Number of grams in 1 mole = 6.23 * 10^23
Now, in 15, it would be: 15 / 6.23 * 10^23 = 2.5 * 10^-24 moles (approx.)
In short, Your Answer would be Option C
Hope this helps!
Answer: The 234.74 grams of sample should be ordered.
Explanation:
Let the gram of 114 Ag to ordered be 
The amount required for the beginning of experiment = 0.0575 g
Time requires to ship the sample = 4.2hour = 252 min(1 hr = 60 min)
Half life of the sample =
= 21 min

![\log[N]=\log[N_o]-\frac{\lambda t}{2.303}](https://tex.z-dn.net/?f=%5Clog%5BN%5D%3D%5Clog%5BN_o%5D-%5Cfrac%7B%5Clambda%20t%7D%7B2.303%7D)
![\log[0.0575 g]=\log[N_o]-\frac{0.033 min^{-1}\times 252 min}{2.303}](https://tex.z-dn.net/?f=%5Clog%5B0.0575%20g%5D%3D%5Clog%5BN_o%5D-%5Cfrac%7B0.033%20min%5E%7B-1%7D%5Ctimes%20252%20min%7D%7B2.303%7D)

The 234.74 grams of sample should be ordered.
1) is sulfuric acid
2)is nitrous acid
3)is hydrochlorous acid
4)is hydrobromous acid
5)is hydrophosphoric acid
6)is fluoric acid
7)is sulfuric acid
8)is chlorous acid
9)is nitric acid
10)is iodic acid
11)is acetous acid
12)is chlorous acid.