Rydberg formula is given by:

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

= 
= 
= 
= 

= 
= 
= 
Now, for  = 2 and
= 2 and  = 5
= 5

= 
= 
= 

= 
= 
= 
Now, for  = 2 and
= 2 and  = 4
= 4

=  
= 
= 

= 
= 
= 
Now, for  = 2 and
= 2 and  = 3
= 3

=  
=  
= 

= 
= 
= 
 
        
                    
             
        
        
        
<span>To find the volume of the plate without accounting for the hole firstly
V = (15.0 cm)(12.5 cm)(0.250 cm) = 46.875 cm^3 
and the volume of the hole is
(pi)(1.25 cm)^2(0.250 cm) = 1.2272 cm^3 
we will subtract the volume of the hole from the rest 45.648 cm^3 
the multiply this by the density of the alloy to find the mass 
(8.80 g/cm^3)(45.648 cm^3) = 401.701 g. 
0.044% of this is Si, so (0.00044)(401.701 g) = 0.17675 g is silicon. 
by the number of atoms and using average atomic mass of silicon and Avogadro's number to find the number of silicon atoms: 
(0.17675 g)(1 mol/28.0855 g)(6.022E23 atoms/1 mol) =3.794E21atoms of Si
3.10% of these are Si-30:(0.0310)(3.794E18 atoms)=1.176E20 atoms of Si-30 and with two significant figures, 1.2E20 atoms.
hope this helps
</span>
        
             
        
        
        
Litmus paper is often used to determine the range of pH of an aqueous solution. Litmus paper specifically contains 10-15 natural dyes, in the presence of acidic solution it turns red, it turns purple when the solution is neutral and blue when dealing with basic solutions. Red litmus paper stays red for a neutral and acidic solution but changes to blue in the presence of alkaline solutions. On the other hand, blue litmus paper turns red when a solution is acidic but stays blue for neutral and alkaline solutions. Since the paper turns purple in the presence of solution 1 we know that is neutral, meanwhile, since it turns blue for the second solution we know that solution II is a base correct answer is C
        
                    
             
        
        
        
In the question, the number of atoms per unit cell is required for:
A) Polonium (Po)
In polonium, the structure is simple cubic, meaning there are 8 corner atoms, which add up to one atom per unit cell.
B) Manganese (Mn)
The structure of the Mn can be considered to be a body centered cubic (BCC) and the number of atoms for this is 8 corner atoms and 1 central atoms, making a total of 2 atoms per unit cell.
C) Silver (Ag)
Silver has a face centered cubic (FCC) unit cell structure, where there are 8 corner atoms and 6 atoms on the faces, so there are a total of 4 atoms per unit cell.
        
             
        
        
        
Answer:
runoff is he draining away of water (or substances carried in it) from the surface of an area of land, a building or structure, etc.
Explanation: