Balmer series-chemistry learners
The Balmer series
Introduction of the Balmer series
The first
rank or the first position, first-class or the class first, are words alluring
to everyone. Because the first is always the best. Similarly, something that
happens for the first time drags everyone's attention. You might be confused
about the repeated use of the word 'first'; yeah, you got the correct doubt.
Today, we are discussing the first discovered series of the hydrogen spectrum.
I hope you can guess it correctly. Okay, this is the Balmer series. And in this
blog post, we discuss only the Balmer series of the hydrogen spectrum.
The Balmer series is the spectroscopic invention of the scientist Johann Jakob Balmer. It occupies second place among the six series of the hydrogen spectrum. You might think that;
Why the first discovered series of the hydrogen spectrum is in the second place?
Since all spectral emission lines in the
Balmer series correspond to the electron transitions from top-level energy
orbits greater than two to the principal quantum number n=2. And we all know
that the classification of spectral series derives from the lower energy state
of the electron during its transition. In the Balmer series, the lower energy
state of the electron or the ground state is the second energy level.
Consequently, it is in second place among the six hydrogen spectral series.
Additional reference:
A beautiful PowerPoint presentation the hydrogen spectral series
An infographic on the common names of the hydrogen emission spectrum
In this
blog post, we will learn about what is Balmer series? And its history, the
Balmer formula, and its significance in astronomy. So, without further delay,
let us discuss the definition of the Balmer series.
 |
| Balmer series diagram |
What is the Balmer series?
The Balmer
series is a hydrogen spectral series. The mathematician Johann Jakob Balmer
discovered it in 1885. Not to mention, you are aware that it is the second
series of the hydrogen spectrum. It signifies the lower energy state of the
hydrogen electron for the Balmer series.
The
hydrogen atoms present in the discharge tube absorb energy from the electric
current that flows through it. It causes the excitation of the hydrogen
electron from the ground state to one of the higher energy orbits with a
quantum number equal to n≥3. After being unstable, the hydrogen electron jumps
back to its initial lower energy position n=2 with the emission of photons of a
definite wavelength. It gives spectral lines in the Balmer series.
 |
| The four colored spectral emissions in the Balmer series |
And all the
spectral emission lines in the Balmer series emit photons with wavelengths
between 400-700 nm. It denotes that the Balmer series occurs in the visible
region of the electromagnetic spectrum.
History of the Balmer series
Since the
1550s, in the smelting of ores, the flame color served as a qualitative
application to identify the chemical substances. Because each chemical element
imparts its characteristic color to the flame when heated. On heating, the
atoms of the chemical substances absorb heat energy that causes the excitation
of its electrons. And while returning to the lower energy state, they give off
their excess energy in the form of light. It shows different colors in the
flame when the wavelength of the emitted light radiation fall in the visible
region.
This method
helped find their chemical composition rather than the amount of substance
present in the ores. But the intensity of light acquired in the process helps
in their quantitative analysis.
In 1666,
Sir Isaac Newton used this atomic emission phenomenon to study the different
colors of sunlight. He used a prism to disperse the sunlight into individual
wavelengths. Then Newton kept a screen to display the solar emission lines. To
which he named it a spectrum.
Later,
Joseph von Fraunhofer used a diffraction grating instead of a Newton prism for
the dispersion of sunlight. He demonstrated the effectiveness of various slits
such as a rectangular slit, single slit, and double slit for spectral
emissions. Moreover, he observed some dark bands in the solar absorption
spectrum with his diffraction grating technique. They were later named
Fraunhofer lines.
Besides,
Anders Jonas Ångström's experiments on solar spectral lines inspired Balmer to
carry out the experiments on the hydrogen atomic spectrum. Angstrom studied the
wavelengths of spectral lines in the solar spectrum and expressed them in units
of 10-10 meters. And this measurement became a unit for atomic length named
after him as Angstrom.
In 1885,
Jakob Balmer discovered an empirical equation to calculate the wavelengths of
hydrogen emission lines in the visible region of the hydrogen spectrum. And it
is termed the Balmer formula.
Additional reference:
What is the history of the atomic emission spectra?
An infographic on the history of the Balmer series
Scientist life history
Johann
Jakob Balmer was a Swiss mathematician. And he was born in Lausen, Switzerland,
on 1 May 1825. He was the elder son of Elizabeth Rolle Balmer and Johann Jakob
Balmer (his father's name was the same as his name).
From
childhood, he had a good command of Mathematics subject. Balmer studied
mathematics at the University of Karlsruhe and the University of Berlin. And at
the University of Basel, he submitted his thesis on the cycloid in 1849. Balmer
spent his entire life as a math teacher in Basel. And he also delivered his
lectures at the University of Basel.
In 1885, he
interpreted an empirical formula to calculate the wavelengths of the hydrogen
emission lines in the visible region. In 1888, Rydberg generalized this Balmer
formula to calculate the wavelengths of all spectral lines of the hydrogen
spectrum. It laid the foundation to discover the other spectral series of the
hydrogen spectrum. The other physicists, Lyman, Paschen, and Brackett,
predicted the hydrogen spectral lines outside the visible region.
For his
contributions to the scientific world, a spectral series of the hydrogen
spectrum named as Balmer series. And his empirical formula and the constant h
of his formula were popularly known as the Balmer formula and the Balmer
constant.
In stellar
classification, the Balmer jump is a valuable theory named after him. In
addition to that, a crater on the moon was also named Balmer in his honor.
Overview of the Balmer series
Balmer is
well renowned for his research on the hydrogen spectral series. The part of the
hydrogen emission spectrum that corresponds to electron transitions from higher
orbicular states n>2 to the energy level with principal quantum number n=2
is a series of spectral lines known as the Balmer series. And the Balmer series
consists of a sequence of spectral emissions in both ultraviolet and visible
regions of the electromagnetic spectrum. Please check out our engaging infographic on Overview of Balmer series.
With the
suggestion of Eduard Hagenbach, he utilized Angstrom’s measurements on solar
emissions to find a formula for the visible spectral lines of hydrogen. It was
popularly known as the Balmer formula. And it computes the wavelengths of the
hydrogen emission lines in the visible region.
 |
| The Balmer formula |
Where,
λ is the wavelength of emitted
spectral lines of hydrogen
h is a
constant known as the Balmer constant
m is a
principal quantum number that equals two
n is an
integer provided n>m. It’s value can be 3,4,5,….,∞
The hydrogen spectrum has four colored spectral lines in the visible region called the hydrogen color spectrum. The wavelengths of these visible spectral lines lie between 400-700 nm. There are innumerable Balmer lines in the ultraviolet zone with wavelengths shorter than 400 nm. In the ultraviolet region, we observe an infinite continuum while approaching 364.506 nm, which is the series limit of the Balmer series.
The
spectral lines with wavelengths shorter than 364.506 nm have not been observed
yet in the Balmer series. Hence, this wavelength is the series limit for the
Balmer series.
Additional reference:
A PowerPoint presentation on the hydrogen emission spectrum
An infographic explaining the Balmer series of the hydrogen spectrum
What do you mean by a series limit?
We all know
the spectrum is an arrangement of wavelengths of emitted light radiations. All
the spectral lines in a series have the same initial principal quantum number.
Series
limit is the region between the starting line and the limiting line of the
series. The starting line is the point at which the atomic line starts, and it
will progress towards higher wavelengths. And at the limiting line, the series
ends. The limiting line is the endpoint where no additional lines will occur in
that series.
Even though the Balmer series occurs in two regions of the electromagnetic spectrum, we usually say the Balmer series is in the visible region. Why?
The Balmerseries of the hydrogen spectrum show spectral emissions in both visible and
ultraviolet regions. But, in our discussions, we generally speak that the
Balmer series is in the visible zone. The reason behind it is;
- Due to the abundance of hydrogen in the universe, we commonly see Balmer series spectral lines in the celestial bodies. The majority of these spectral emission lines lie in the visible part of the hydrogen spectrum. The human eye detects them easily without much effort.
- The spectral emissions in the ultraviolet region correspond to higher energy transitions, which have not yet been discovered completely.
Hence, due to the predominance importance of the visible part of the Balmer series over the ultraviolet region, we generally speak that the Balmer series occurs in the visible zone of the electromagnetic spectrum.
Additional reference:
Hydrogen
visible spectrum
In the
visible zone, we observe four spectral lines at wavelengths 656nm, 486nm,
434nm, and 410nm correspond to electron transitions from energy levels such as
3 to 2, 4 to 2, 5 to 2, 6 to 2 giving characteristic red, aqua, blue and violet
colored emissions in the hydrogen spectrum. This portion of the Balmer series
is also known as the visible hydrogen spectrum.
 |
| Hydrogen visible spectrum |
These transitions are also referred to sequentially by Greek letters. The electron transition from the third stationary orbit to the second is known as Hydrogen-alpha or H-α. And Hydrogen beta refers to the electron movement from the fourth main energy level to the second level. The hydrogen gamma spectral line is due to electron transference from the fifth stationary configuration to its early level. Finally, the hydrogen delta spectral line occurs by the electron transition from the sixth orbit to the ground state n=2.
 |
| Hydrogen visible spectrum table |
Out of
these four spectral emissions, we observe an intense spectral line during the
electron movement from the third energy level to the second level. It is a
bright red spectral line in the emission spectra of hydrogen or the ionization
nebula.
 |
| The picture of Orion nebula |
Indeed the
most famous H II region is the Orion nebula. It is an interstellar matter
consisting of ionized hydrogen atoms cloud that gives a reddish-pink colored
visible hydrogen spectral emission line. The color variation is due to the combining
effect of other electron transitions in the visible zone.
At
sufficient temperature, a significant number of hydrogen atoms absorb energy
that corresponds to the energy difference between the third and second
stationary levels. It results in the electron transition between these two
static configurations with the emission of a spectral line having a longer
wavelength at 656 nm in the hydrogen atomic spectrum. Therefore, it is the most
intense spectral line in the hydrogen visible spectrum with a bright red color.
Which part of the electromagnetic spectrum can we see? And why?
The
electromagnetic spectrum is the patterned arrangement of all kinds of light
radiations in the increasing (or decreasing) order of their wavelengths and
frequencies. From them, the human eye can see visible light radiations with
wavelengths ranging from 380nm to 700 nm. Only these wavelengths can stimulate
the human eye's retina during light observation.
The visible
part of the light consists of seven-colored radiations of the sunlight. They
are violet, indigo, blue, green, yellow, orange, and red.
The wavelength
variations of these seven-colored radiations are below;
 |
| The wavelengths data of light in the visible region |
UV Balmer spectrum
The
electron transitions from the principal quantum number n>6 to the Balmer
series ground state n=2 emit spectral lines in the ultraviolet region of the
electromagnetic spectrum. Further, Balmer colleagues Wilhelm Vogel and William
Huggins confirmed these spectral emissions in the white stars. Moreover, these
electron transitions are also symbolized sequentially with Greek letters shown
in the following table.
 |
| The Ultraviolet Balmer Spectrum |
The spectral line formed due to the electron transition from the static configuration n=7 to the normal state n=2 is known as hydrogen epsilon. The hydrogen zeta emission line is due to the electron transition from top energy level n=8 to the ground state n=2 at a wavelength of about 389 nm. Similarly, the electron movement from n=9 to n=2 results in a spectral line named hydrogen eta. Finally, the spectral emission that results from n=∞ to the Balmer series ground state n=2 at 364.5 nm is the series limit of the Balmer series.
 |
| The UV Balmer series table |
From the spectral studies, Balmer found that a single wavelength has relation to every spectral line in the visible region of the hydrogen spectrum. And that wavelength is 364.5 nm. Hence, it is also known as the Balmer break.
Why does the Balmer series of the hydrogen spectrum occur in two regions, namely ultraviolet and visible but all the other hydrogen spectral series occur in a single zone of the electromagnetic spectrum?
The
hydrogen spectrum consists of six spectral series in the ultraviolet, visible,
and infrared regions. Except for the Balmer series, the other series show
spectral emissions in a single zone of the electromagnetic spectrum. But the Balmer
series show spectral emissions in two zones such as ultraviolet and visible
regions of the electromagnetic spectrum. Before discussing its reason, let us
first discuss the Balmer series briefly.
In 1885,
the scientist Johann Jakob Balmer discovered a series of hydrogen spectral
lines in the visible region. Later his colleagues found a few more spectral
emissions in the ultraviolet region. These spectral emission lines occur during
the electron transition from the top energy levels with principal quantum
number n>2 to the second stationary orbit of the hydrogen spectrum. Hence,
the series of all the spectral emissions that occur with the ground state
quantum number n=2 during the electron transitions is known as the Balmer
series.
The
electron transitions from higher energy orbits to lower stationary states
proceed with the emission of the photons of definite wavelengths.
If the
wavelengths of the emitted light radiations lie between 400-and 700 nm, then
the spectral lines occur in the visible region. Similarly, the spectral
emission lines with wavelengths below 400 nm give spectral lines in the
ultraviolet zone.
According
to the quantum theory of radiations, the energy of a photon varies inversely
with the wavelength of the emitted light radiations.
If the
energy gap between the two successive stationary orbits is high, then the
emitted photon gives a spectral line at a shorter wavelength. So, the electron
transitions from the highest energy orbits, such as n>6, give spectral
emissions in the ultraviolet region. Consequently, the electron transitions
till n=6 give spectral emissions in the visible part.
It is the
peculiar condition of the Balmer series giving spectral lines in two different
regions of the electromagnetic spectrum. Whereas in the remaining five hydrogen
spectral series, the higher electron transitions give spectral emission lines
in the same part of the electromagnetic spectrum as the lower transitions.
Additional reference:
Why does the Lyman series lie in the ultraviolet region?
Balmer break
In the
stellar continuum spectrum, the Balmer break is the intensity difference on
either side of the Balmer series limit nearly at 364.5 nm.
It occurs
due to the bound-free absorption of hydrogen electrons at the ground state n=2
resulting in their complete ionization.
The bound
free absorption in the Balmer series results in the continuum absorption at
wavelengths shorter than 364.5 nm. It is otherwise called Balmer discontinuity.
The other hydrogen spectral series show continuum discontinuity at wavelengths
shorter than their series limit. But, the Balmer break is observed apparently
in the ultraviolet region of the hydrogen spectrum.
The
temperature and density of the absorption region affect the strength of
continuum absorption or the size of the Balmer break.
In cooler
stellar regions, the density most strongly affects the continuum strength. It
helps to classify stars based on their surface gravity. However, in hotter
stars, the temperature affects the discontinuity strength immensely more than
the density.
Balmer series formula
From the
history of the Balmer series, we can understand that physicists' experiments on
the atomic emission spectrum started in the 1550s. But they lacked an empirical
formula to imagine the wavelengths of spectral lines of an element. In 1885,
the Balmer equation was the first empirical formula discovered to estimate the
wavelengths of spectral emissions in the hydrogen spectrum. The Balmer equation
was given by the mathematician Johann Jakob Balmer.
His great
benefaction to astronomy and chemistry was discovering an empirical formula to
estimate the spectral lines in the visible region of the hydrogen spectrum in
1885. It calculated the spectral emissions wavelengths when the electron alters
from a stationary configuration higher than two to an orbicular state that is
equal to n=2. To do so, he took Angstrom's atomic size calculations into
account. According to Angstrom, the radius of an atom is equal to 10-10
meters.
So, the
Balmer formula for the spectral emissions in the Balmer series of the hydrogen
line spectrum is below;
 |
| The Balmer series formula |
In the
above formula, h is the Balmer constant, and its value is 364.506 nm. This
Balmer constant value interprets the series limit of the Balmer series. During
his spectral studies, Balmer found that a single wavelength has a relationship
with all the spectral emission lines in the visible region of the Balmer
series. And that wavelength is 364.506 nm. In addition to that, there are no
more spectral lines in the Balmer series with wavelengths shorter than this
figure. So, the wavelength 364.506 nm is the series limit of the Balmer series.
In simple terms, the Balmer series ends at this point.
m is an
integer. And m=2. It implies the ground state of the electron in the Balmer
series for the electron transitions is two.
n is an
integer. And its value must be greater than m. The value of n starts with 3 and
ends at infinity.
According
to the Balmer equation, the wavelengths of spectral lines are obtained when any
integer value higher than two was squared and then divided by itself squared
minus four. And the achieved value should be multiplied by the Balmer constant
value of 364.506 nm.
The
wavelengths of hydrogen spectral lines gave accurate results for spectral
emissions in the visible region. The Balmer equation gives precise results for
the four visible hydrogen spectral lines. But, when the value of m is greater
than 6, the electron transition gives spectral emission in the ultraviolet
region. The Balmer equation calculations are slightly inaccurate for the
spectral emissions of the ultraviolet region.
Meanwhile,
Hagenbach informed Balmer that Angstrom got a hydrogen spectral line at 397 nm
for electron transitions from n=7 to the second stationary state. It paved the
way for the modification of the Balmer equation.
Additional reference:
What is the Rydberg-Ritz combination principle?
What are the six series of the hydrogen spectrum?
Rydberg formula- a generalization to Balmer equation
In 1888,
the physicist Johannes Rydberg generalized the Balmer formula with the necessary
modifications. The Rydberg formula helps to calculate the wavelengths of all
spectral lines that occur in the hydrogen spectrum with the help of an
empirical fitting parameter known as the Rydberg constant.
The Rydberg
equation involves a simple reciprocal mathematical rearrangement necessary to
get accurate results for calculating the wavelengths of hydrogen spectral lines
in the Balmer series along with all the other series of the hydrogen spectrum.
The Rydberg
equation to calculate the wavelengths of Balmer series spectral lines is below;
 |
| The Rydberg equation for Balmer series |
Where,
RH is
a Rydberg constant for the hydrogen atom and its value equal to 10973731.57 m-1
n is an
non-negative positive integer with value starts from 3 and proceeds towards
infinity.
λ
is the wavelength of emitted spectral lines in the hydrogen spectrum
What is the Rydberg constant of a hydrogen atom?
The Rydberg
constant of the hydrogen atom is a constant quantity that should be used with
every spectral line of the hydrogen spectrum. The above formula shows it.
 |
| The relationship between the Balmer constant and the Rydberg constant of the hydrogen atom |
For infinitely heavy hydrogen nucleus,
it implies;
 |
| The calculation of the Rydberg constant value |
As a final
note, the Rydberg constant is a constant number. And it is the ratio of two
square to Balmer constant h. It helps to calculate the wavelengths of all
hydrogen spectral lines that occur in the hydrogen emission spectrum.
The Rydberg
formula used generally to calculate the wavelengths of all spectral lines in
the hydrogen spectrum is
 |
| The Rydberg formula |
Where,
λ = wavelength of the emitted electromagnetic radiation
n1 = lower energy level of the electron
transition
n2 = higher energy level of the electron
transition
RH= Rydberg constant
Hydrogen- alpha
It is the
first line that occurs in the Balmer series of the hydrogen spectrum. Hence,
the initial Greek symbol α denotes it. Jointly, we call it the hydrogen alpha
spectral line. And in rare circumstances, we also call it the Balmer alpha line
that indicates the Balmer series of the hydrogen spectrum.
It is a deep
red colored spectral line that occurs in the visible region at 656.28 nm in
air. And it is the brightest hydrogen spectral line in the hydrogen visible
spectrum. The electron transition from the third stationary orbit to the second
energy level of the hydrogen atom gives this hydrogen-alpha spectral line. Due
to the small energy difference between these two second and third stationary
orbits, hydrogen-alpha spectral lines occur at a longer wavelength with the
least energy emission in the Balmer series. So, we can see it at the end of the
visible region of the electromagnetic spectrum.
 |
| Hydrogen alpha emission in the Balmer series |
It is the
most intense spectral emission in the visible region of the hydrogen spectrum.
It indicates that it is the most abundant spectral emission of the hydrogen
spectrum. At sufficient temperature, a large number of the hydrogen atoms
prefer to transit between the third and second energy levels of the hydrogen
atoms. It enhances the number of transitions between these two stationary
orbits. It, in turn, increases the number of photons emissions. But, it does
not impact the number of spectral lines at 656.28 nm. Since the values of
principal quantum numbers for the electron transition are unchanged, we get
only one red-colored bright spectral line. To conclude, the intensity of the
spectral line is directly proportional to the number of atoms participating in
the electron transition.
 |
| The hydrogen alpha transition in the Balmer series of the hydrogen spectrum |
The
ionization energy of one hydrogen atom is 13.6 eV. And the energy difference
between the n=1 to n=3 is 12.1 eV. So, a large number of hydrogen atoms prefer
to ionize before their transition between the third and first stationary levels
of the hydrogen atom. It favors the ejection of electrons from the hydrogen
atoms to produce H+ ions. Again, the formation of new hydrogen atoms takes
place by the combination reaction of the electron and the proton. The majority
of newly formed hydrogen atoms proceed with n=3 to n=2 electron transition
after recombination. Hence, it will emit the most intense bright red colored
hydrogen alpha spectral line. It intimates that the hydrogen alpha emissions occur when the hydrogen gas ionization occurs. Therefore, the red spectral
emission lines help astronomers trace the ionized electron clouds in the
astronomical bodies.
Additional reference:
Why does the hydrogen alpha spectral line seem doublet with a high-resolution spectrometer?
What is the importance of Lyman-alpha line?
Importance of the hydrogen alpha line:
As
mentioned earlier, hydrogen-alpha emissions indicate ionized hydrogen atoms
clouds and the emission nebulae and help astronomers identify them.
Due to the
hydrogen abundance in the universe, hydrogen-alpha emissions help to observe
the sun’s atmosphere features, including solar prominences and chromosphere.
Hydrogen alpha filter
The
hydrogen-alpha filter is an optical filter used to filter out the
hydrogen-alpha wavelength by stopping all the unnecessary wavelengths of
sunlight.
The
hydrogen-alpha filters are dichroic interference filters made with multiple
vacuum deposited layers. It relies on the interference of internal light
reflections that reflect between that surfaces.
In short,
the hydrogen alpha filters transmit the narrow bandwidth of light radiations by
focusing on hydrogen alpha wavelengths.
They are
used in astrophotography and to reduce light pollution in solar observations.
Additional reference:
What is the hydrogen spectral series?
Fine structures of the Balmer series spectral lines:
The
electron transitions in the hydrogen atom result in spectral lines in the
atomic spectrum of hydrogen. We observe a single spectral line corresponding to
a single electron transition with spectrometers. But, the high-resolution
spectrometers show the splitting of the main spectral line into two or more
components with a slight variation in the wavelengths. These diverged spectral
lines are known as fine structures of the main spectral line.
Hydrogen is
a simple element with a single electron in it. In the presence of a magnetic
field, we observe closely spaced spectral lines doublet for the hydrogen
spectral lines. These are the hydrogen fine structures.
The
hydrogen fine spectrum is the dissociation of the hydrogen main spectral line
into its constituent spectral emission lines.
The
hydrogen spectrum consists of six series of spectral lines. They occur in the
visible, ultraviolet, and infrared regions of the electromagnetic spectrum. In
this blog article, we will discuss the spectral splitting of the Balmer series.
In the
Balmer series, we all know red, aqua, blue, and violet-colored spectral
emission lines in the visible region. Out of them, the red-colored spectral
line at 656.28 nm shows spectral splitting in the presence of the magnetic
field. The high-resolution spectrometer shows a pair of closely spaced spectral
lines for the hydrogen alpha line. They are hydrogen-alpha fine structures.
 |
| The hydrogen alpha fine structures |
According
to atomic structure theories, an atom consists of a hefty nucleus at the center
with revolving electrons in discrete energy levels. The revolution of electrons
around the nucleus in fixed orbits generates a magnetic field in the atom.
The
interaction of the spinning electron with the magnetic field generated by the
electron's orbital motion around the nucleus causes the splitting of spectral
lines in the atom.
The hydrogen-alpha emission occurs due to the electron transition from the higher energy orbit n=3 to the lower energy state n=2. And the emitted light radiation at 656.28 nm gives the alpha spectral line in the hydrogen spectrum. The splitting of the spectral line takes place when the emitted light radiation is affected by the atom's magnetic field. The powerful spectrometer detects it.
Additional reference:
What do you mean by the hydrogen spectral line?
Applications of the Balmer series
- The study of the Balmer series is most useful in astronomy. As many stellar objects generally show the Balmer series spectral lines. Due to the plethora of hydrogen in the universe, these are the most intense spectral lines compared with the other element's spectral lines.
- It plays a significant role in the spectral classification of stars like surface gravity and composition. Based on its predominance, the relative strength of these spectral lines determines the star's surface temperature.
- It helps to find out the radial velocities of the celestial bodies due to the Doppler shifting of the Balmer series.
- The Balmer series helps to detect binary stars, exoplanets, star clusters, galaxy clusters, etc. In addition to that, its close analysis helps to identify unknown astronomical bodies.
- It also estimates the redshifts of galaxies or quasars.
- The occurrence of emission or absorption lines of the Balmer series depends on the nature of the astronomical object. In the stars with a surface temperature of about 10,000 kelvins, the Balmer series absorption lines are seen. But, in the spectra of irregular galaxies, H II regions, the Balmer lines are the spectral emission lines.
Maximum and minimum wavelengths of Balmer series:
The electron transitions from n ≥3 to
n=2 result in the emergence of a sequence of spectral lines in the Balmer
series of the hydrogen spectrum. Consequently, the n1 and n2 values of the
Balmer series vary from 2 to infinity.
The maximum wavelength for the Balmer series is 656 nm, and the minimum wavelength is 364.5 nm. Hence, the
limits of the Balmer series are 656 nm and 364.5 nm.
 |
| The maximum and minimum wavelengths of spectral lines in the Balmer series |
Position of the Balmer series in the hydrogen spectrum
The
hydrogen atomic spectrum consists of a sequence of spectral lines arranged in
the decreasing order of their wavelengths and the increasing order of their
frequencies. And the hydrogen spectrum consists of six series named after the
scientists who discovered them. The six series of the hydrogen spectrum are;
- Lyman series
- Balmer series
- Paschen series
- Brackett series
- Pfund series
- Humphreys series
On
observing the sequential order of the hydrogen spectral series, we understand
that the Balmer series is in second place.
Here is a trick to remember all the six series of the hydrogen spectrum without much effort.
The order
of hydrogen spectral classification intimates the electron's ground state
during the electron transition. In the Balmer series, the principal quantum
number value for the ground state of the electron is n=2. Hence, it is in
second place in the hydrogen spectral series.
In the same way, the Lyman series having electron's ground state principal quantum number n=1 is in the first place.
 |
| The six series of the hydrogen spectrum |
Final thoughts
This blog article discussed about the Balmer series of the hydrogen spectrum in detail. We hope that this blog post is helpful
to you. And what else do you know about the Balmer series of the hydrogen spectrum? Kindly share
your knowledge with us in the comments below. And also, you can visit our blog
https://jayamchemistrylearners.blogspot.com/ regularly for more engaging topics
of chemistry. We add new posts regularly to our blog. To not miss any updates,
kindly follow us. We will notify you immediately.
Most importantly, you can ask your
questions on the hydrogen spectral series topic in the post comment section and also
on our Instagram page. We are happy to hear from you and will answer you.
For more fascinating chemistry topic
visuals, please visit and follow our Instagram page @chemistrylearners and
Pinterest page @kameswariservices.
Final thoughts
Most importantly, you can ask your
questions on the hydrogen spectral series topic in the post comment section and also
on our Instagram page. We are happy to hear from you and will answer you.
For more fascinating chemistry topic
visuals, please visit and follow our Instagram page @chemistrylearners and
Pinterest page @kameswariservices.