Rydberg formula is given by:

where,
= Rydberg constant = 
= wavelength
and
are the level of transitions.
Now, for
= 2 and
= 6

= 
= 
= 
= 

= 
= 
= 
Now, for
= 2 and
= 5

= 
= 
= 

= 
= 
= 
Now, for
= 2 and
= 4

= 
= 
= 

= 
= 
= 
Now, for
= 2 and
= 3

= 
= 
= 

= 
= 
= 
Metallic bonds are found in metals like zinc.
Explanation:
Given the mass of HCl is ---- 0.50 g
The volume of solution is --- 4.0 L
To determine the pH of the resulting solution, follow the below-shown procedure:
1. Calculate the number of moles of HCl given by using the formula:

2. Calculate the molarity of HCl.
3. Calculate pH of the solution using the formula:
![pH=-log[H^+]](https://tex.z-dn.net/?f=pH%3D-log%5BH%5E%2B%5D)
Since HCl is a strong acid, it undergoes complete ionization when dissolved in water.

Thus, ![[HCl]=[H^+]](https://tex.z-dn.net/?f=%5BHCl%5D%3D%5BH%5E%2B%5D)
Calculation:
1. Number of moles of HCl given:

2. Concentration of HCl:

3. pH of the solution:
![pH=-log[H^+]\\=-log(0.003425)\\=2.47](https://tex.z-dn.net/?f=pH%3D-log%5BH%5E%2B%5D%5C%5C%3D-log%280.003425%29%5C%5C%3D2.47)
Hence, pH of the given solution is 2.47.
Answer:When you look at the periodic table, each row is called a period (Get it? Like PERIODic table.). All of the elements in a period have the same number of atomic orbitals. For example, every element in the top row (the first period) has one orbital for its electrons.
Explanation: