Frontiers in organic and Analytical chemistry

About the conference:

The International Conference on Organic and analytical chemistry, to be held in Kuala Lumpur, Malaysia during November 27-28, 2019. Since their start, Larix Conferences have been the leading international gatherings on various disciplines especially in Chemistry and analytical chemistry. This conference is meant to reflect the diversity and energy of the current field, encompassing, inter alias, structure and function, mechanisms, theory, catalysis, spectroscopy, materials, and synthesis. Invited speakers represent a wide collection of scientific disciplines, unified in large measure by the desire to understand the interconnection of structure, reactivity and mechanisms. Organic Chemistry 2019 will be a highly interactive, friendly and collegian atmosphere, which encourages collaborations and nurtures younger scientists. All attendees are invited to present their latest, research results. This comprehensive and multidisciplinary approach plays a pivotal role in the development of chemical sciences, expanding their boundaries, and reflects on the vibrant and enlightening scientific discussions usually held in Organic Chemistry 2019 meetings.

This would be a very pleasant place to spend a week in October. We hope to see you at Kuala Lumpur in 2019.

Why Attend Organic Chemistry 2019

·       This Organic Chemistry 2019 event will provide an opportunity to build and expand your network with various people and gives chance to make collaboration with other universities and research labs.

·       This Organic chemistry conference 2019 will also help you to meet the experts in the relevant field of study.

·       This conference plays a major role in your business development and maximizes profits.

·       Along with that, develop focused and timely programs, products, and services that engage those involved in Chemistry, Organic chemistry, and related fields, enhance communication and market our programs, products, and services more effectively, expand global impact by developing the infrastructure to deliver technical programming for targeted international audiences.

What are some interesting facts about chemistry?

Chemistry is a fascinating science full of unusual trivia. A list of some of the most fun and most interesting chemistry facts.

• The only solid elements that assume liquid form ​at room temperature are bromine and mercury. However, you can melt gallium by holding a lump in the warmth of your hand.

• Unlike many substances, water expands as it freezes. An ice cube takes up about 9% more volume than the water used to make it.
• If you pour a handful of salt into a full glass of water, the water level will actually go down rather than overflowing the glass.
• Similarly, if you mix half a liter of alcohol and half a liter of water, the total volume of the liquid will be less than one liter.
• There is about 1/2 lb or 250 g of salt (NaCl) in the average adult human body.
• A pure element takes many forms. For example, diamond and graphite both are forms of pure carbon.
• Many radioactive elements actually glow in the dark.
• The chemical name for water (H2O) is dihydrogen monoxide.
• The only letter not appearing on the periodic table is J.
• Lightning strikes produce O3, which is ozone, and strengthen the ozone layer of the atmosphere.
• The only two non-silvery metals are gold and copper.
• Although oxygen gas is colorless, the liquid and solid forms of oxygen are blue.
• The human body contains enough carbon to provide 'lead' (which is really graphite) for about 9,000 pencils.
• Hydrogen is the most abundant element in the universe, while oxygen is the most abundant element in the earth's atmosphere, crust, and oceans (about 49.5%).
• The rarest naturally-occurring element in the earth's crust may be astatine. The entire crust appears to contain about 28 g of the element.
• Hydrofluoric acid is so corrosive that it will dissolve glass. Although it is corrosive, hydrofluoric acid is considered to be a 'weak acid'.
• One bucket full of water contains more atoms than there are buckets of water in the Atlantic ocean.
• Approximately 20% of the oxygen in the atmosphere was produced by the Amazon rainforest.
• Helium balloons float because helium is lighter than air.
• Bee stings are acidic while wasp stings are alkaline.
• Hot peppers get their heat from a molecule called capsaicin. While the molecule acts as an irritant to mammals, including humans, birds lack the receptor responsible for the effect and are immune to the burning sensation from exposure.
• It's possible to die from drinking too much water.
• Dry ice is the solid form of carbon dioxide (CO2).
• Liquid air has a bluish tint, similar to water.
• You can't freeze helium simply by cooling it to absolute zero. It will freeze if you apply extremely intense pressure.
• By the time you feel thirsty, you've already lost about 1% of your body's water.
• Mars is red because its surface contains a lot of iron oxide or rust.
• Sometimes hot water freezes more quickly than cold water. A high school student documented the effect, which bears his name (the Mpemba effect).

What is the difference between Chemistry and Green Chemistry?

Chemistry is the study of matter, the way matter (atoms and molecules and compounds) interacts to give rise to a whole range of processes. It is also the study of the behavior of individual atoms, molecules and compounds. Chemistry is also known as the “central science” because the study of Chemistry is also important for Physics and Biology. Chemistry is, basically, the study of all the different types of atoms, molecules, compounds and the processes and phenomena that happen when they interact.

Green Chemistry is a specific field of Chemistry involving the study of atoms, molecules, compounds and determining whether the usage of such matter is safe for the environment.

DIFFERENCES:

1. Chemistry is a very broad science, meaning that it covers a large range of theories, whereas, Green Chemistry is only a fraction of Chemistry.
2. Chemistry aims at developing chemicals for the welfare of the humans, whereas Green Chemistry aims at developing chemicals for the welfare of the humans but in the same time, not adversely affecting the environment.

What is the difference between polymer science, polymer chemistry, and polymer physics?

Polymer Science is a generic term covering the various subdivisions of the subject.
 Polymer chemists are mostly interested in the task of making plastic substances from their precursor chemicals; by reacting ethylene, propene or other hydrocarbons with catalysts under appropriate conditions Eg high pressure. Plastics or thermoplastics are typically made by free radical chain reactions. 
In contrast polymer resins or thermosets, another class of man made polymers, are made by cross linking various reactive momomers or oligomers together, Eg polyurethane paint when spread into a thin film eg on a wall, undergoes a cross linking reaction to form a resin; the crosslinking reaction is induced by atmospheric oxygen. Resins unlike plastics are essentially one big molecule ! 

That's why there are few if any solvents for them. In contrast plastics can be softened with solvents being linear in their structure at the molecular level. 
The distribution of polymer chain lengths in a given plastic material is largely controlled by the kinetics of the free radical chain reaction, in the monomer to polymer conversion process. So you've got to like reaction kinetics if you want to be a polymer chemist !  Lots of physical chemistry. 
Rubbers are amorphous thermoplastics above their glass transition temperature. Polymer spectroscopy carried out for polymer material identification purposes is also a speciality within the field of polymer chemistry. Also gel permeation chromatography or gpc which is another polymer characterization technique. 
 
Polymer blending is another subject within polymer materials science. Also thermal analysis, using techniques such as TG, DTA, & DSC. 

Turning to polymer engineering. Polymer engineers often have degrees in mechanical engineering. Polymer engineering concerns itself with the moulding or castings of polymer materials into useful engineering products. Things such as plastic buckets, rainwater goods, tyres, yacht hulls, plastic bottles, aircraft windows,  plastic shopping bags, sneakers, shoes, car panels, train seats, aircraft interiors, vending machine tea cups, toys, sports equipment etc, the list goes on !


Polymer technology has a slightly broader remit covering subjects in addition to polymer engineering ranging from polymer additives for car engine oil ( Eg star polymers ), to medical polymers (Eg pace makers ), polymers in electronics, household paints, fabrics, rope, polythene beakers for hydrofluoric acid. In fact any useful application.

What are the different research fields in Inorganic Chemistry?

Research fields in Inorganic Chemistry are as wide as Inorganic Chemistry itself. Everything you read about in Chemistry textbooks were discovered at one time or another.
So research in Inorganic Chemistry will cover the chemistry & some of the physical properties of each of the individual elements in the periodic table and their compounds, apart from the organic chemistry of carbon.
A major discovery in Inorganic Chemistry could be something like the first example of the compound of an element having a new oxidation state. Or the first example of a compound of the element Neon. No known compounds of Neon exist. It is the least reactive element in The Periodic Table. So a major discovery like that would be accepted for publication in a major international scientific journals. Eg. Nature. A discovery like that may make it to the TV news as a story stating that for the first time in history all known elements are now known to form chemical compounds.

Here are a few research areas :

• Main group reaction chemistry
• Inorganic vibrational spectroscopy
• Transition metal chemistry
• Magnetochemistry
• Theoretical inorganic chemistry
• Non-aqueous solvent chemistry
• High temperature chemistry
• Fused salt chemistry
• Solid state chemistry
• Battery technology
• Nuclear chemistry
• Trans-Uranium chemistry
• Lanthanides and Actinides
• Organometallic chemistry
• Heterogeneous catalysis
• Homogeneous catalysis
• Materials chemistry
• Glass science
• Organoboranes
• Cryptands
• X-ray crystallography
• Electronic spectroscopy in inorganic chemistry
• Matrix isolation and low temperature chemistry
• Energetic materials

What is the use of food chemistry in food tech?

If you are a food technologist and still you are asking this question then you must question your knowledge.

And if not then read the following explanation:

Food technology is the field in which one deals with processing and preservation of food. One also reads about different processing techniques and technologies. Any technology will get acceptance only if it solves some need and also has minimum side effects. Taking this point in mind one can really understand the role of food chemistry in food technology.

Firstly, food chemistry helps one understand the basic structure and properties in components of foods e.g the carbohydrate fats and proteins. Upon understanding the chemistry of the components of food one can really understand the impact a processing technique is going to have on the food. Let us take example of heat processing techniques like pasteurization. In this case the extent of the treatment will be depending on extent of adverse effects that can be allowed on these components. So from where do we get the idea of these adverse effects. The answer is food chemistry which gives us useful insights into mailard reaction, denaturation of proteins and oxidation of fats. And the use of food chemistry is not just limited to above examples but also includes the vitamins, food pigments and antioxidants.

So, basically this is how useful, food chemistry is in food technology.

What are R groups in organic chemistry?

R group in Organic chemistry refers to the alkyl group which may be either straight chain ( like -CH3, -C2H5,etc) or branched [ isopropyl -CH(CH3)2 or neobutyl -C(CH3)3,etc]. This alkyl group is due to the substitution of a hydrogen atom of alkane ( from alkane to alkyl) with any other functional group. 
Even aromatic compounds do contain alkyl group. Just a simple example if we remove a hydrogen atom from benzene (C6H6) we get a phenyl group which is an alkyl group (-C6H5) therefore in chlorobenzene, phenyl is the R part.

For example if you look at this reaction:

only the top left OH group is reacting so a simplified version would be

for example if you look at this reaction

only the top left OH group is reacting so a simplified version would be

What is the meaning of charge transfer resistance in electrochemistry?

Charge transfer resistance has to do with the process of electron transfer from one phase (e.g. electrode) to another (e.g. liquid). Take, for example, the electrolysis of water. On the cathode hydrogen is reduced to H2 gas. 

It takes energy to remove electrons from a metal electrode and join them with the protons to produce hydrogen. Thus, the process of transferring electrons from the electrode to the hydrogen ions in the liquid phase has a certain resistance associated with it and this resistance can be given in ohms just like regular ohmic resistance. That resistance is charge transfer resistance.

What are the differences (pros/cons) of solution and solid state NMR for structural biology?

A particular advantage of solid-state NMR and NMR spectroscopy, in general, is its ability to provide information on the dynamics of biomolecules.

Pros:

In solid-state NMR spectroscopy, motions on a broader timescale (from the nano- to the millisecond timescale and beyond) can be detected. For example, the nano- to millisecond timescale can readily be explored by measuring the spin–lattice relaxation in the laboratory (R1) or the rotating frame (R1r), while real-time solid-state NMR allows the course of protein refolding or of enzymatic reactions to be followed.

There is no protein size limit in solid-state NMR spectroscopy.

In liquid state, the anisotropic interactions give rise to fluctuating local fields which themselves manifest as relaxation effect in the spectra. In contrast, the rapid tumbling of molecules is absent and the anisotropic interactions give rise to a distribution of resonances reflecting the distribution of molecular orientations within the sample. These distributions, on analysis, can provide wealth of information: the anisotropic interactions experienced by the nuclear spin, the local electron distribution around a nucleus, and relative proximity between individual spins.
Using the structural and dynamic information encoded in the interactions experienced by the nuclear spin, it is possible to determine how the structure and dynamics present within membrane proteins relates to their function, and how these molecular species interact within the membrane.

Cons:

In solution state, resolution is provided mostly by nature because the anisotropic spin interactions that can broaden NMR lines are motionally averaged. In the solid state, motional averaging is less efficient because of reduced mobility, and considerably broadened spectra are acquired in this case. Line narrowing, therefore, must be performed artificially: manipulation of the Hamiltonian to dissect the anisotropic interactions or to suppress their influence on NMR spectra in a controlled manner.

With regards to the protein size, technical challenges remain to be solved before dynamics can be routinely measured at atomic resolution in large proteins.

Additionally, with respect to solution state NMR  integral membrane proteins embedded in detergent micelles are still challenging.

How can we determine that a particular neutral molecule is a strong base or a nucleophile?

Nucleophilicity roughly parallels basicity. The trick lies within the word roughly. A base (in a BL sense) attacks protons, whereas a nucleophile attacks anything else.

From here, try to think about this: basicity is a subset of nucleophilicity. All nucleophiles are Lewis bases; they donate a lone pair of electrons. A “base” (or, better said, a Brønsted base) is just the name we give to a nucleophile when iit forms a bond to a proton (H+). Therefore, when we are talking about basicity and nucleophilicity, we are describing these two types of events.

If basicity can be described by means of equilibria, nucleophilicity can be described in terms of reaction rates. Acid-base reactions are fast equilibria.

Many reactions of nucleophiles are not reversible and two more factors must be accounted for, though, when dealing with nucleophiles: their steric hindrance and solvent effects. The more sterically hindered a nucleophile, the weaker it is. The more polar (or, even worse, the more protic) a solvent, the weaker the nucleophile.

Is IR spectroscopy applicable for all compounds?

The change in dipole moment is first and foremost criteria to get IR spectrum of any compound. The compounds which give rise to change in the dipole moment upon absorption of IR radiation, will give IR spectra. The compounds which do not give rise to change in the dipole moment upon absorption of IR radiation, will not give IR spectra. For example, the symmetrical stretching of C=C bond in ethylene will not produce any change in dipole moment of the molecule. Hence, this mode of vibration is IR inactive. This also tell why trans-dichloroethane does not show C=C stretching whereas cis-dichloroethane shows C=C stretching. However, both cis and trans-dichloroethane show C-H and C-Cl stretching upon IR absorption. Carbon monoxide and Iodine chloride (I-Cl) show IR absorption but hydrogen (H2), Nitrogen (N2), Oxygen (O2), Chlorine (Cl2) and other symmetrical diatomic molecules do not show IR absorption. A large change in dipole moment gives rise to strong absorption.

In summary, only those compounds give rise to IR absorption or IR spectra which have-

1.      Permanent dipole moment

2.      Which show change in dipole moment upon absorption of IR radiation

3.      Which do not possess center of symmetry

Atom for atom, which element is the most dangerous for a human?

Mercury has two faces. As a metal it is not particularly dangerous even if you swallow it. However, lost into the environment, it gets divided into finer and finer droplets, then metabolized into methylmercury by bacteria. This is one of the most hideously dangerous toxins known.

It is a biologically cumulative neurotoxin. Once it is in an animal or human it cannot be excreted. It concentrates up the food chain, so bigger fish that eat little fish become more contaminated … and that's why eating tuna more than twice a week is no longer recommended. Even the remotest ocean now has significant mercury pollution, from human effluents and coal fired power station chimneys.

A tiny drop of the pure chemical goes straight through latex gloves, straight through almost any protective clothing, straight through skin, and causes a hideous death over the next few months. In contrast Polonium or Plutonium is dangerous only if you swallow or inhale it. Accumulating a toxic level through polluted food leads to an even more protracted fate.

What are future potential of green chemistry?

In 1998, Paul Anastas (who then directed the Green Chemistry Program at the US EPA) and John C. Warner (then of Polaroid Corporation) published a set of principles to guide the practice of green chemistry.

The twelve principles address a range of ways to reduce the environmental and health impacts of chemical production, and also indicate research priorities for the development of green chemistry technologies.

The principles cover such concepts as:

·         the design of processes to maximize the amount of the raw material that ends up in the product;

·         the use of renewable material feedstocks and energy sources;

·         the use of safe, environmentally benign substances, including solvents, whenever possible;

·         the design of energy efficient processes;

·         avoiding the production of waste, which is viewed as the ideal form of waste management.

The twelve principles of green chemistry are:

1.      Prevention. Preventing waste is better than treating or cleaning up waste after it is created.

2.      Atom economy. Synthetic methods should try to maximize the incorporation of all materials used in the process into the final product.

3.      Less hazardous chemical syntheses. Synthetic methods should avoid using or generating substances toxic to humans and/or the environment.

4.      Designing safer chemicals. Chemical products should be designed to achieve their desired function while being as non-toxic as possible.

5.      Safer Solvents and auxiliaries. Auxiliary substances should be avoided wherever possible, and as non-hazardous as possible when they must be used.

6.      Design for energy efficiency. Energy requirements should be minimized, and processes should be conducted at ambient temperature and pressure whenever possible.

7.      Use of renewable feedstocks. Whenever it is practical to do so, renewable feedstocks or raw materials are preferable to non-renewable ones.

8.      Reduce derivatives. Unnecessary generation of derivatives—such as the use of protecting groups—should be minimized or avoided if possible; such steps require additional reagents and may generate additional waste.

9.      Catalysis. Catalytic reagents that can be used in small quantities to repeat a reaction are superior to stoichiometric reagents (ones that are consumed in a reaction).

10.  Design for degradation. Chemical products should be designed so that they do not pollute the environment; when their function is complete, they should break down into non-harmful products.

11.  Real-time analysis for pollution prevention. Analytical methodologies need to be further developed to permit real-time, in-process monitoring and control before hazardous substances form.

12.  Inherently safer chemistry for accident prevention. Whenever possible, the substances in a process and the forms of those substances should be chosen to minimize risks such as explosions, fires, and accidental releases.

What is Inductively coupled plasma mass spectrometry?

ICP Mass Spectroscopy is an analytical technique that uses plasma to ionize the sample. The ionized sample is then separated based on their charge to the mass ratio in the mass spectrometer. Thus, the ICP-MS has a high-temperature ICP source (for plasma) and a mass spectrophotometer. The ICP source converts the atoms of the sample into ions.

ICP torch:

Most common ICP uses the Argon gas system to generate plasma. The instrument has ICP (or Plasma) torch where the argon gas flows. The ICP torch is surrounded by RF load coils. The RF load coils are connected to the Radio-frequency generator. As the power is generated from the generator, there would be a generation of the oscillating electric and magnetic fields at the end of the torch. It will be followed by the generation of a spark that would ionize the argon gas flowing through the torch to argon ions. These ions will get caught in the oscillating field and collide with the other argon ions which would generate the Plasma or discharge.

Sample Ionisation:

The sample used in ICP-MS is in aerosol form. This form can be achieved by aspirating the liquid sample or dissolved sample into the Nebulizer. This aerosol is transferred towards the plasma torch, it is desolvated, and then the solid sample will be converted to a gaseous state which would be ionized at the end of the torch. The plasma or the argon discharge has a temperature of around 6000-10000 K and acts as an excellent ion source. However, most of the ions generated by the plasma are positively charged and thus, negatively charged ions such as Cl, F, Br, I, etc. cannot be ionized and analyzed easily with the help of ICP-MS.

Once the elements in the sample are converted into ions, they are then brought into the mass spectrometer via the interface cones.

The purpose of these cones are to sample the center portion of the ion beam coming from the ICP torch. A shadow stop will block the extra photons coming from the ICP torch. Thought the ICP-MS are very accurate and beneficial for analyzing compounds, the small orifice (opening) of the Sampler cone and Skimmer cone limits the amount of the solid sample dissolved (0.2% TDS) and analyzed. If the total dissolved solids in the sample are high, then the orifice of the cone will be blocked. Now, the ions are focused towards the entrance of mass spectrometer. This is facilitated by the Electrostatic lens which is positively charged. As the ions ejected from the ICP are positively charged, they would get repelled by the parallel positively charged electrostatic plated and focused on entrance aperture or slit of the mass spectrometer. The most commonly used Mass Spectrometer is Quadrupole mass analyzer 

Why is absorption spectroscopy preferred over emission spectroscopy?

The term 'Spectrum' generally refers to electromagnetic spectrum which includes all the frequencies of electromagnetic radiation. Earlier, the term was restricted to light only, but later, it was modified to include other waves too, such as sound waves. Wavelengths range from a pico meter to hundreds of mega meters. It includes visible spectrum in its ambit, which deals with all the wavelengths that are visible to the naked eye. Other types of radiation include radio waves, gamma rays, X-rays, and so on.

The other types of spectra are energy spectrum, mass spectrum, frequency spectrum, etc. The important types of spectra generally mentioned in this context are emission spectrum and absorption spectrum. There are several differences between emission spectrum and absorption spectrum, other than the uptake or loss of energy. Let us have a look at all of them.

The Basics

When energy in the form of light, heat, or chemical agents is given to an element, the electrons of its atoms accept the energy and go to higher energy levels. However, these electrons have to emit energy in order to return to their ground state, since the excited state is unstable. The frequencies of light emitted in such a case constitute the emission spectrum. When an electron comes down from an excited state to the ground state, it emits a photon of energy. The energy of this photon depends on the difference between the energy levels of the excited state and ground state of that electron.

Electrons of an element which are in the ground state may absorb incident energy in order to reach a higher energy state. The frequencies of light transmitted through this substance, with dark bands showing absorbed light, constitute the absorption spectrum of the substance.

Underlying Process

Emission is the process where a substance gives off or emits radiation when it is heated or treated chemically. The level of emission of a substance depends on its spectroscopic composition and temperature.

Absorption is the process where the electrons of a substance absorb or take up the energy wavelengths incident on them. The atomic and molecular structure of the material governs its level of absorption, along with the amount of electromagnetic radiation, temperature, solid crystal structure, and intermolecular interactions.

Description of Spectrum

● The emission spectrum of a gas is represented by a collection of separate colored lines, with dark spaces between them. The lines are the parts of the spectrum where emission occurs and photons are emitted, while the dark spaces are the parts where there is no emission, hence the darkness. The difference in colors is due to the variation of the energy levels of the electrons.
● In case of ionic solutions, the spectrum will consist of discrete colored bands instead of lines, since the substance here is a compound with different atoms, which together produce complex colors. Emission spectrum is different for different elements subjected to the same source of energy, due to the difference in the excitation energies of the different electrons of the substances. This is why the light emitted by each substance is different.
● The frequency of emission spectrum are frequencies of light that are dependent on the energy of the emission. The energy of the photons emitted is related to its frequency by the following formula:
E = hʋ
Where E = energy of the photon
h = Planck's constant
ʋ = frequency of the photon
This shows that the frequency of a photon is directly proportional to its energy.
● Emission spectra can be divided into two: line spectrum and continuous spectrum. When the spectrum appears as a series of lines, which are separated by black spaces, it is called a line spectrum. When the spectrum consists of a wide range of colors in a particular wavelength range or interval, it is called continuous spectrum.

● The absorption spectrum of an element is represented by a continuous band of colors with separate dark lines between them. The entire band represents the total light that is focused on the element. The dark lines are the parts of the spectrum where the electrons absorb light photons, hence, there is absence of light at these parts. The remaining colored parts of the spectrum represent the parts of the incident light that has not been absorbed, and hence, appear as wavelength-specific colors.
● The reason for this pattern is that, all electrons of an atom are at different energy levels at any given time. The energy difference between two energy levels of each electron is different. When light of any wavelength is focused on these atoms, each electron will absorb only that photon with the same energy as this energy difference. The rest of the photons are not absorbed, i.e., these photons are scattered. These dark lines correspond to the same positions where the colored lines of the atom's emission spectrum would occur.
● Absorption spectra can be measured in terms of their frequency, wavelength, or wave number.
● There are two types of absorption spectra: atomic absorption spectrum and molecular absorption spectrum. Atomic absorption spectrum is the spectrum obtained when free atoms (generally gases) absorb wavelengths of light. Molecular absorption spectrum on the other hand is the spectrum that is seen when molecules of a substance absorb wavelengths of light (generally ultraviolet or visible light).

Common Applications of Emission and Absorption Spectroscopy

Spectroscopy is the study of the spectrum of a substance to investigate more about its properties. Both absorption and emission spectroscopy have a number of uses.

Emission Spectrum

● To identify a substance: Every substance emits lights of different wavelengths. To identify the given substance, light is focused on it or the substance is heated. This causes the electrons to get excited and jump to a higher orbit. The energy emitted by these electrons while returning to their ground states is compared to the characteristic colors of the elements, and the chemical composition of the substance is determined.
● To study the composition of stars: The emission spectra of stars can be recorded and then compared with standard emission spectra of known elements to determine their chemical composition.

Absorption Spectrum

● To identify a substance and determine its concentration: An unknown substance can be identified by focusing light of a particular wavelength on it, and then studying the absorption spectrum of the substance. Since substances absorb light only from a particular wavelength or wavelength range, the wavelength of light focused on them is important. This spectrum can be compared with a set of reference values for identification. These reference values are known absorbance values of common elements and compounds. The concentration of the substance in the sample can also be determined.
● To study the composition of stars: The light emitted by stars and planets passes through their atmosphere, where some of it is absorbed by the gases. When the absorption spectra of these gases is recorded and compared to the reference spectra values of gases, the composition of these planets or stars can be determined.
● Remote sensing: Absorption spectroscopy can be used to collect details of the land, including attributes such as forest cover, health of forests or exposed rock surfaces, without any individual actually setting foot on it. When light is focused on the land terrain and its absorption spectra is recorded, it can be used to extract information about the terrain. This is done by comparing the recorded values with reference values of absorbance shown by land with forest cover or exposed rock. In fact, the absorbance values vary depending on the type of the forest, a healthy vegetation will show different values compared to an unhealthy forest cover. It can also provide details of atmospheric composition.

Both absorption and emission spectroscopy are exact opposites of each other. Since the electronic configurations of elements are different, the spectrum values of these elements will be their 'atomic fingerprint', i.e., it will be unique to each element. It is said that absorption spectrum is the 'photographic negative' of emission spectrum, because the wavelengths that are missing in absorption spectrum are seen in the emission spectrum.