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

= 
= 
= 

= 
= 
= 
Answer:
Environment A is not undergoing succession, and Environment B is.
Explanation:
Ecological succession is a gradual process in which ecosystems significantly change over time. Ecological succession is a term used by scientists to describe the change in the structure of a community of different species, or ecosystem. This concept of ecological succession stems from a desire to understand the patterns of change in large and complex ecosystems like forests and how they can exist in places known to be recently formed, such as volcanic islands.
In environment A, the ecosystem is not really changing, organisms are merely returning to their natural habitat. It does not represent any change in the ecosystem.
In environment B, the original ecosystem has become grossly modified, first by the appearance of lichen and mosses and subsequently by grasses shrubs and animals. These sequence of events correlate well with the idea of ecological succession presented in the opening paragraph hence environment B is undergoing ecological succession.
If it isn't using energy, it's called diffusion
Answer:
<h2>The electrons in beryllium and magnesium are too strongly bound to get excited by flame. Hence, these elements do not impart any color.</h2>
Hope you could understand.
If you have any query, feel free to ask.