Browsing Category


What is Human Genome Project [HGP] ? 1

What is Human Genome Project [HGP] ?

blue catterpillar

Photo by Quang Nguyen Vinh on

Human Genome Projects

an international collaboration that successfully determined, stored, and rendered publicly available the sequences of almost all the genetic content of the chromosomes of the human organism, otherwise known as the human genome. The Human Genome Project (HGP), which operated from 1990 to 2003, provided researchers with basic information about the sequences of the three billion chemical base pairs (i.e., adenine [A], thymine [T], guanine [G], and cytosine [C]) that make up human genomic DNA (deoxyribonucleic acid). The HGP was further intended to improve the technologies needed to interpret and analyze genomic sequences, to identify all the genes encoded in human DNA, and to address the ethical, legal, and social implications that might arise from defining the entire human genomic sequence.

Ionic Bond
Science Chemistry

What is Ionic Bonding?

Ionic bonding is a type of chemical bonding that involves the electrostatic attraction between oppositely charged ions, and is the primary interaction occurring in ionic compounds. It is one of the main bonds along with Covalent bond and Metallic bonding. Ions are atoms that have gained one or more electrons (known as anions, which are negatively charged) and atoms that have lost one or more electrons (known as cations, which are positively charged). This transfer of electrons is known as electrovalence in contrast to covalence. In the simplest case, the cation is a metal atom and the anion is a nonmetal atom, but these ions can be of a more complex nature, e.g. molecular ions like NH+
4 or SO2−
4. In simpler words, an ionic bond is the transfer of electrons from a metal to a non-metal in order to obtain a full valence shell for both atoms.

Over View of Ionic Bond

Atoms that have an almost full or almost empty valence shell tend to be very reactive. Atoms that are strongly electronegative (as is the case with halogens) often have only one or two empty orbitals in their valence shell, and frequently bond with other molecules or gain electrons to form anions. Atoms that are weakly electronegative (such as alkali metals) have relatively few valence electrons, which can easily be shared with atoms that are strongly electronegative. As a result, weakly electronegative atoms tend to distort their electron cloud and form cations.

Formation of Ionic Bond

Ionic bonding can result from a redox reaction when atoms of an element (usually metal), whose ionization energy is low, give some of their electrons to achieve a stable electron configuration. In doing so, cations are formed. An atom of another element (usually nonmetal) with greater electron affinity accepts the electron(s) to attain a stable electron configuration, and after accepting electron(s) an atom becomes an anion. Typically, the stable electron configuration is one of the noble gases for elements in the s-block and the p-block, and particular stable electron configurations for d-block and f-block elements. The electrostatic attraction between the anions and cations leads to the formation of a solid with a crystallographic lattice in which the ions are stacked in an alternating fashion. In such a lattice, it is usually not possible to distinguish discrete molecular units, so that the compounds formed are not molecular in nature. However, the ions themselves can be complex and form molecular ions like the acetate anion or the ammonium cation.

For example, common table salt is sodium chloride. When sodium (Na) and chlorine (Cl) are combined, the sodium atoms each lose an electron, forming cations (Na+), and the chlorine atoms each gain an electron to form anions (Cl−). These ions are then attracted to each other in a 1:1 ratio to form sodium chloride (NaCl).

Na + Cl → Na+ + Cl− → NaCl
However, to maintain charge neutrality, strict ratios between anions and cations are observed so that ionic compounds, in general, obey the rules of stoichiometry despite not being molecular compounds. For compounds that are transitional to the alloys and possess mixed ionic and metallic bonding, this may not be the case anymore. Many sulfides, e.g., do form non-stoichiometric compounds.

Many ionic compounds are referred to as salts as they can also be formed by the neutralization reaction of an Arrhenius base like NaOH with an Arrhenius acid like HCl

NaOH + HCl → NaCl + H2O
The salt NaCl is then said to consist of the acid rest Cl− and the base rest Na+.
The removal of electrons from the cation is endothermic, raising the system’s overall energy. There may also be energy changes associated with breaking of existing bonds or the addition of more than one electron to form anions. However, the action of the anion’s accepting the cation’s valence electrons and the subsequent attraction of the ions to each other releases (lattice) energy and, thus, lowers the overall energy of the system.

Ionic bonding will occur only if the overall energy change for the reaction is favorable. In general, the reaction is exothermic, but, e.g., the formation of mercuric oxide (HgO) is endothermic. The charge of the resulting ions is a major factor in the strength of ionic bonding, e.g. a salt C+A− is held together by electrostatic forces roughly four times weaker than C2+A2− according to Coulombs law, where C and A represent a generic cation and anion respectively. The sizes of the ions and the particular packing of the lattice are ignored in this rather simplistic argument.

Structures of Ionic Bond


Representation of ionic bonding between lithium and fluorine to form lithium fluoride. Lithium has a low ionization energy and readily gives up its lone valence electron to a fluorine atom, which has a positive electron affinity and accepts the electron that was donated by the lithium atom. The end-result is that lithium is isoelectronic with helium and fluorine is isoelectronic with neon. Electrostatic interaction occurs between the two resulting ions, but typically aggregation is not limited to two of them. Instead, aggregation into a whole lattice held together by ionic bonding is the result.

Ionic compounds in the solid state form lattice structures. The two principal factors in determining the form of the lattice are the relative charges of the ions and their relative sizes. Some structures are adopted by a number of compounds; for example, the structure of the rock salt sodium chloride is also adopted by many alkali halides, and binary oxides such as magnesium oxide. Pauling’s rules provide guidelines for predicting and rationalizing the crystal structures of ionic crystals.

Strength of Ionic Bond

For a solid crystalline ionic compound the enthalpy change in forming the solid from gaseous ions is termed the lattice energy. The experimental value for the lattice energy can be determined using the Born–Haber cycle. It can also be calculated (predicted) using the Born–Landé equation as the sum of the electrostatic potential energy, calculated by summing interactions between cations and anions, and a short-range repulsive potential energy term. The electrostatic potential can be expressed in terms of the interionic separation and a constant (Madelung constant) that takes account of the geometry of the crystal. The further away from the nucleus the weaker the shield. The Born-Landé equation gives a reasonable fit to the lattice energy of, e.g., sodium chloride, where the calculated (predicted) value is −756 kJ/mol, which compares to −787 kJ/mol using the Born–Haber cycle.[2][3] In aqueous solution the binding strength can be desribed by the Bjerrum or Fuoss equation as function of the ion charges, rather independent of the nature of the ions such as polaribility or size [4] The strenght of salt bridges is most often evaluated by measurements of equilibria between molecules containing cationic and anionioc sites, most often in solution. [5] Equilibrium constants in water indicate additive free energy contributions for each salt bridge. Another method for the identification of hydrogen bonds also in complicated molecules is crystallography, sometimes also NMR-spectroscopy.

air pollutions
Diseases Science

10 Most Common Diseases caused by Air Pollution in 2019

Air Pollution is one of the most widespread pollution and is one of the inevitable ones. Being an ever-pervading medium and carrier, air can transfer the pollutants very fast in no time; making it almost impossible for any person breathing in the polluted air, to avoid the infection. Though the pollutant level, reaction to the pollutants and infestation of the pollutant based diseases in every person is different; the fact that air pollution can have injurious effects on the human body can just not be ignored.

This post shall be focusing on 10 such diseases caused by the air pollution and what pollutants cause them.

#1 — Asthma:

This is one of the most common diseases that can affect the humans breathing in the polluted air. This is a chronic disease in which inflammation is caused in the air passages of the human body and the person finds it difficult to breathe. Heavy breathing while doing normal routine activities and strenuous ones are some of the basic symptoms of the disease.

Asthma is caused by the particulate matter, oxides of sulfur and nitrogen and ground-level ozone. Tobacco smoke can also be a cause of the same and the parents, friends, family members and other people in close contact with the patient should refrain from smoking in his or her presence.

One of the things that the asthma patients can do is use the Fresh Air Bottles in order to give a blast of pure and fresh air to their lungs and respiratory system. However, the consultation with a physician first is advised.

#2 — Lung Cancer:

Owing to the presence of various carcinogens in the air, the lungs can get infested with them which in turn can lead to lung or pulmonary cancer. The disease involves uncontrolled growth of the cells in one or both of the lungs causing a reduction in the oxygen-carrying capacity and malfunctioning in the complete working of the respiratory system.

Though the lung cancer cures depend on the type of cancer and the level of infection in the lungs, the Fresh Air Cans may be a possible solution to reduce the effect of such carcinogens in the polluted air.

#3 — COPD (Chronic Obstructive Pulmonary Disease)

COPD is caused by the air pollution in which the air passages and air sacs or the alveoli change their shape and become distended. Thus, the patient finds it difficult to breathe even while sitting or doing nothing. Emphysema and Chronic Bronchitis are two types of COPD which are common and can lead to cancer and premature deaths as well.

The most affected people are the people working in the mines, quarries and docks etc that are in constant contact with the dust, fine dust, and diesel fumes etc.

Using air purifiers and Fresh Air Cans may be prevention but complete cure requires intensive doctoral involvement and medicines.

#4 — Leukemia:

It is a disease (the type of cancer) caused by exposure to the benzene vapors and is fatal as well. The WBCs or the White Blood Cells get increased in the amount owing to persistent infection caused by the infection and the respiratory tract is infected heavily.

#5 — Pneumonia:

10 Most Common Diseases caused by Air Pollution in 2019 4
Polluted air also carries bacteria that get inhaled into the respiratory tract which in turn causes pneumonia. The disease might get worse with continued breathing of the polluted air and the disease might get worse with some other disease caused by the pollution.

Using air filters wherever possible and Fresh Air Bottles might be a probable prevention of the disease and might prove beneficial for the patients as well. But immediate doctor assistance is important and advised in all cases.

#6 — Birth defects and immune system defects:

There are a number of defects that can occur in the newborn as well as unborn babies owing to exposure to the polluted air and breathing of polluted air by the pregnant mother respectively. The babies born in the areas with air pollution will have lower immunity against the infections, cough, and cold and might also exhibit some inborn allergies as well.

The pregnant ladies can consult with the doctors and use the air filters as well as the Fresh Air Cans which are immunity boosters and nullify the effect of the pollutants on the respiratory system.

#7 — Autism:

Recent studies have revealed that air pollution can also cause Autism — a disease in which the patient has a tendency to live alone.

#8 — Weakening of Lung Function:

If the level of the air pollution is not high, there might be a general or gradual weakening of the lung function in the people breathing in the polluted air. This can be exhibited in a number of forms such as allergies, panting while doing heavy or normal daily routine activities and very low immunity to a cough and cold etc.

Auzair Fresh Air Bottles may help in counter-effecting all such infections and thus help the body to regain its strength.

#9 — Cardiovascular Diseases:

Owing to the presence of a number of poisonous substances in the polluted air, poisonous gases, and particulate matter, the people living in the polluted environment exhibit a lot of cardiovascular diseases of various kinds. The extent of exposure to the pollutants can determine the degree of the disease and infection.

#10 — Premature Deaths:

It has been found that pollutants in the air can lead to premature deaths owing to different reasons such as asphyxiation and extreme reactions caused by the body to the pollutant matter. Every year a huge number of premature deaths are registered all across the world owing to the pollution.

Though the ever pervading air pollution is really difficult to be handled and fought with, the Fresh Air Bottles can be a big help. These bottles are filled with pure air, every single breath of which sends a boost of freshness and life down to the cellular level.