<span>Begin by classifying which energy level, and indirectly principal quantum number, n, resembles to the N shell.
no. of orbitals =n2
In your case, the fourth energy level will contain
n=4⇒no. of orbitals= 4^2=16
The number of subshells is given by the principal quantum number.
no. of subshells=n
In your case, the fourth energy level will have
no. of subshells = 4 this is the answer
to check:
the fourth energy shell will can hold a thoroughgoing of no. of electrons=2⋅42=32 e−</span>
<h2>The required balanced equation:</h2><h2>

</h2>
Explanation:
• Propane when reacts with oxygen it gives carbon dioxide and water.
- In order to make the equation balanced at both ends of the equation,
Add 4 as a coefficient before on L.H.S (Left Hand Side) of Equation.
• Therefore, the required balanced equation is:
Propane, when added with 5 molecules of Water, yields 3 molecules of Carbon Dioxide and 4 molecules of water, as shown in the below equation -

Answer:
a
Explanation:
The formation of ion occurs when an atom that is said to be neutral gains or losses electrons.
At the time it gains electrons, it is regarded that a negative ion (anion) is formed.
When it loses electron, it is regarded that a positive ion (cation) is formed.
Atomic number = No of protons and electrons occurring in a neutral atom.
Given that:
Protons = 14
electron = 18
Net Charge = no of proton - no of electron
= 14 - 18
= -4
Mass number = 14 + 15 = 29
So, the chemical symbol = 
For ion with
27 proton, 32 neutrons and 25 electrons
Net charge = 27 - 25
= +2
Mass number = 27 + 32 = 59
Thus, the chemical symbol = 
Considering you should look and not touch in museums... A.