# Confused about the number of absorption lines

• YMMMA
In summary, the number of spectral lines an atom can exhibit due to transitions between 3 levels, 4 and 5 levels, and also in emission is three.
YMMMA

## Homework Statement

If an atom in energy level 1, how many absorption spectral lines can an atom exhibit due to transition between 3 levels? How about 4 and 5 levels? And also in emission?

Concept

## The Attempt at a Solution

I am confused one book says it can absorb a photon to the third level at once, or to n=2, so there is only 2 possible transitions. Another book says it can absorb once to n=3, n=2, and from n=2 to n=3, so there are 3 possible transitions in total. How am I supposed to count the possible transitions? Here’s a question I encountered, but I need to know how to solve any problems of this kind. Any help is appreciated, Thanks in advance!

YMMMA said:
one book says it can absorb a photon to the third level at once, or to n=2, so there is only 2 possible transitions. Another book says it can absorb once to n=3, n=2, and from n=2 to n=3, so there are 3 possible transitions in total.
It might come down to the exact wording of the statements. Can you post extracts?

I forgot to post the problem,too.

#### Attachments

• 872EA81C-5EF3-49A8-AB6A-F6B2BE7BA67B.jpeg
23.2 KB · Views: 304
Here they are.

#### Attachments

• image.jpg
43.9 KB · Views: 275
• image.jpg
41.5 KB · Views: 291
• image.jpg
46.1 KB · Views: 276
• image.jpg
36.3 KB · Views: 274
YMMMA said:
I forgot to post the problem,too.
The number of spectral lines are asked "if all transitions were possible ".

ehild said:
The number of spectral lines are asked "if all transitions were possible ".
So they are indeed three possible transitions.

YMMMA said:
So they are indeed three possible transitions.
Yes.

YMMMA
YMMMA said:
Here they are.
I see no inconsistency. Some of these texts are considering only transitions from a given level, not all transitions between the levels in the set.

So why in question 5 didn’t we include transitions from n=3 to n=2 and n=2 to n=1, and n=3 to n=1...

YMMMA said:
So why in question 5 didn’t we include transitions from n=3 to n=2 and n=2 to n=1, and n=3 to n=1...
Because that question specifies transitions from level 4.
This is not the same as asking for all emission lines, since that would include 3->2, 3->1 and 2->1.

Got the difference, thanks!

## 1. What are absorption lines?

Absorption lines are dark lines seen in a spectrum of electromagnetic radiation, such as light, caused by the absorption of specific wavelengths of light by atoms or molecules in the material being observed.

## 2. How do absorption lines form?

Absorption lines form when atoms or molecules in a material absorb specific wavelengths of light, causing those wavelengths to be missing from the final spectrum. This absorption occurs when electrons in the atoms or molecules are excited to higher energy levels, leaving gaps in the lower energy levels that correspond to the missing wavelengths.

## 3. Why is it important to study absorption lines?

Studying absorption lines allows scientists to analyze the composition, temperature, and motion of objects in space, such as stars, galaxies, and interstellar gas. It also provides valuable information about the physical conditions and processes taking place in these objects.

## 4. How do scientists determine the number of absorption lines?

Scientists use spectroscopy to observe and analyze the absorption lines in a spectrum. They can then compare the observed lines to known patterns and characteristics of different elements and molecules to determine the number and type of absorption lines present.

## 5. Can the number of absorption lines change over time?

Yes, the number of absorption lines can change over time due to various factors such as changes in the physical conditions of the object being observed, the motion of the object, and the presence of other elements or molecules that may affect the absorption process.

Replies
8
Views
4K
Replies
16
Views
3K
Replies
0
Views
476
Replies
11
Views
1K
Replies
5
Views
484
Replies
13
Views
2K
Replies
1
Views
1K
Replies
5
Views
1K
Replies
7
Views
2K
Replies
8
Views
2K