0 Comments

## Who proposed modern periodic table?

Henry Moseley. Explanation: Modern periodic law states that the chemical and physical properties of elements are the periodic function of their atomic numbers. It was proposed by Henry Moseley in the year 1913 from his X-ray studies.

#### Is the modern periodic table given by Moseley or Bohr?

Hint: Periodic table is the arrangement of all the known elements according to their properties in such a way that the elements of similar properties are grouped together in a tabular form. Complete answer: Various scientists gave various forms to design periodic table, some of them are given below: According to Lavoisier classification, elements can be classified simply in metals and non metals.

Metals are the one which have the tendency of losing the electrons and nonmetals have the tendency of gaining the electrons. According to Newland octet rule, elements can be arranged in atomic mass as if elements are arranged in increasing order of atomic mass their properties of every eighth element was similar to the first element of the octet.

For example properties of lithium are similar to eighth element sodium. Lother’s Meyer curve was between atomic weight and atomic volume. This curve proposed that the physical properties of the elements are periodic functions of their atomic weight as elements having similar properties occupy a similar position on the curve.

According to Mendeleef’s periodic table, physical and chemical properties of elements are the periodic function of their atomic weight. It arranged the known elements at that time in a systematic manner that is in horizontal rows and vertical columns. It also gave encouragement to the discovery of new elements as some gaps were left in it.

Modern periodic table or modified Mendeleef’s periodic table was proposed by Moseley. It is based on atomic number. It states that physical and chemical properties of the elements are periodic functions of their atomic number. Long form or extended form of periodic table based in the Bohr Bury electronic configuration concept and atomic number.

It was proposed by Rand and Werner. This table consists of 7 periods and 18 groups. Thus, the correct option is D. Note: According to Proust’s hypothesis, all the elements are made up of hydrogen, so it can be given as: \ where n is a even number. According to the Dobereiner trial rule, the atomic weight of the middle element is nearly equal to the average atomic weight of the first and third element in a triad.

For example:

 Element Cl Br I Atomic weight \ \ \

As \,

## Who is the father of the modern periodic table Moseley?

Common Questions about Dmitri Mendeleev and Henry Moseley – Q: Why is Dmitri Mendeleev regarded as the father of the periodic table? In his periodic table, Mendeleev had left some notable gaps, such as the spaces just below aluminum and silicon. These gaps were meant for yet-to-be-discovered elements.

• When those elements were discovered later, it was found out that the properties of the new elements matched Mendeleev’s predictions.
• This cemented his legacy as the father of the periodic table.
• Q: Who was Henry Moseley? Henry Moseley is the scientist most directly responsible for realizing that the structure of the atom is key to understanding the elements themselves; it is the number of protons in the nucleus of an atom that determines the identity of each element, and not the atomic mass.

Q: How did Henry Moseley solve the riddle of Mendeleev’s periodic table? Moseley developed a special method of determining the charge of an atom’s nucleus using x-ray radiation. He applied his x-ray technique to measure the integer charge on elemental nuclei, and ordered the elements based on that number, rather than using atomic mass.

#### Who is the father of modern periodic table Bohr?

The modern periodic table was given by: No worries! We‘ve got your back. Try BYJU‘S free classes today! No worries! We‘ve got your back. Try BYJU‘S free classes today! Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses No worries! We‘ve got your back. Try BYJU‘S free classes today! : The modern periodic table was given by:

#### Did Bohr invent the periodic table?

A mathematical map – In many instances in the history of science, grand predictions based on novel equations have turned out to be correct. Somehow math reveals some of nature’s secrets before experimenters find them. Antimatter is one example, the expansion of the universe another.

1. In Mendeleev’s case, the predictions of new elements emerged without any creative mathematics.
2. But in fact, Mendeleev had discovered a deep mathematical map of nature, for his table reflected the implications of quantum mechanics, the mathematical rules governing atomic architecture.
3. In his textbook, Mendeleev had noted that “internal differences of the matter that comprises the atoms” could be responsible for the elements’ periodically recurring properties.

But he did not pursue that line of thought. In fact, over the years he waffled about how important atomic theory was for his table. But others could read the table’s message. In 1888, German chemist Johannes Wislicenus declared that the periodicity of the elements’ properties when arranged by weight indicated that atoms are composed of regular arrangements of smaller particles.

So in a sense, Mendeleev’s table did anticipate (and provide evidence for) the complex internal structure of atoms, at a time when nobody had any idea what an atom really looked like, or even whether it had any internal structure at all. By the time of Mendeleev’s death in 1907, scientists knew that atoms had parts: electrons, which carried a negative electric charge, plus some positively charged component to make atoms electrically neutral.

A key clue to how those parts were arranged came in 1911, when the physicist Ernest Rutherford, working at the University of Manchester in England, discovered the atomic nucleus. Shortly thereafter Henry Moseley, a physicist who had worked with Rutherford, demonstrated that the amount of positive charge in the nucleus (the number of protons it contained, or its “atomic number”) determined the correct order of the elements in the periodic table.

• Atomic weight was closely related to Moseley’s atomic number — close enough that ordering elements by weight differs in only a few spots from ordering by number.
• Mendeleev had insisted that those weights were wrong and needed to be remeasured, and in some cases he was right.
• A few discrepancies remained, but Moseley’s atomic number set the table straight.
You might be interested:  6Th Pay Commission Pay Scale Table

At about the same time, the Danish physicist Niels Bohr realized that quantum theory governed the arrangement of electrons surrounding the nucleus and that the outermost electrons determined an element’s chemical properties. Physicist Niels Bohr revised the periodic table in 1922. QWerk/Wikimedia Commons Similar arrangements of the outer electrons would recur periodically, explaining the patterns that Mendeleev’s table had originally revealed. Bohr created his own version of the table in 1922, based on experimental measurements of electron energies (along with some guidance from the periodic law).

### What did Moseley discover?

In 1913, while working at the University of Manchester, he observed and measured the X-ray spectra of various chemical elements using diffraction in crystals. Through this, he discovered a systematic relation between wave- length and atomic number. This discovery is now known as Moseley’s Law.

## Who is the father of modern periodic table and why is he called that way?

Periodic Table – Dmitri Ivanovich Mendeleev is the father of periodic table. The first detailed form of the periodic table was developed by Mendeleev (based on mass number) but later Henry Gwyn Jeffrey’s Moseley made a new periodic table based on atomic number. Mosley is called the father of modern periodic table.

#### Was Mendeleev and Moseley first?

Summary – Mendeleev vs Moseley Periodic Table – The development of modern periodic table was not a single step development and it has many improvements time after time. The first well-arranged periodic table was proposed by Dimitri Mendeleev in 1869. Then the key to the modern periodic table was proposed by Henry Moseley in 1913.

### Why is the modern periodic table called Bohr?

It follows Bohr’s idea of grouping elements into four categories depending on their electrical configuration, the modern periodic table is sometimes known as Bohr’s table.

#### Who invented the periodic table in science?

© JacobH/iStock.com The periodic table was invented by Russian chemist Dmitri Mendeleev in 1869. However, prior to Mendeleev, chemists had been pondering for decades how to classify the elements, Beginning in 1789, Antoine Lavoisier began classifying elements by their properties.

Johann Wolfgang Döbereiner showed in 1817 that elements could be arranged by their atomic weight into triads such that, for example, strontium had an atomic weight between those of calcium and barium, In 1862 the French geologist Alexandre-Émile-Béguyer de Chancourtois proposed a periodic table of the elements in which the atomic weights of the elements could be plotted on a cylinder with a circumference of 16 units, the atomic weight of oxygen,

Atomic weights were used by English chemist John Newlands in 1864 in classifying the elements. After arranging the elements in order by atomic weight, Newlands noted that every eighth element seemed to have similar chemical properties. By analogy with the seven-note musical scale, he called this the law of octaves.

1. Mendeleev built on this work in arranging the elements according to atomic weight and their properties, but he also paid special attention to an element’s valence (the number of single bonds an element can form).
2. His 1869 table contained 17 columns (or groups, as they are now known).
3. He revised this into an eight-group table in 1871.

In his 1871 table, Mendeleev correctly predicted that the then known atomic weights of 17 elements were wrong. He also predicted the existence of three then unknown elements, scandium, gallium, and germanium, and their properties based on gaps in his table.

### What did JJ Thomson discover?

In 1897 Thomson discovered the electron and then went on to propose a model for the structure of the atom. His work also led to the invention of the mass spectrograph.

#### What did Niels Bohr discover about the periodic table?

Niels Bohr | Biography, Education, Accomplishments, & Facts Niels Bohr proposed a of the in which the was able to occupy only certain orbits around the nucleus. This atomic model was the first to use theory, in that the electrons were limited to specific orbits around the nucleus.

Bohr used his model to explain the spectral lines of, Niels Bohr the with that could only have specific stable orbits. This model of the atom was the first to incorporate theory. That electrons could only occur in specific orbits explained why elements such as emitted and absorbed light at specific wavelengths.

Niels Bohr, in full Niels Henrik David Bohr, (born October 7, 1885,, Denmark—died November 18, 1962, Copenhagen), Danish physicist who is generally regarded as one of the foremost physicists of the 20th century. He was the first to apply the concept, which restricts the energy of a system to certain discrete values, to the problem of and molecular structure.

1. For that work he received the for Physics in 1922.
2. His manifold roles in the origins and development of physics may be his most-important contribution, but through his long career his involvements were substantially broader, both inside and outside the world of,
3. Bohr was the second of three children born into an upper middle-class Copenhagen family.
You might be interested:  Bedroom With Study Table

His mother, Ellen (née Adler), was the daughter of a prominent Jewish banker. His father, Christian, became a professor of at the University of Copenhagen and was nominated twice for the Nobel Prize. Enrolling at the University of Copenhagen in 1903, Bohr was never in doubt that he would study physics.

Research and teaching in that field took place in cramped quarters at the Polytechnic Institute, leased to the University for the purpose. Bohr obtained his doctorate in 1911 with a dissertation on the theory of metals. On August 1, 1912, Bohr married Margrethe Nørlund, and the marriage proved a particularly happy one.

Throughout his life, Margrethe was his most-trusted adviser. They had six sons, the fourth of whom,, shared a third of the 1975 Nobel Prize for Physics in recognition of the of the atomic nucleus proposed in the early 1950s. Bohr’s first contribution to the emerging new idea of quantum physics started in 1912 during what today would be called postdoctoral research in England with at the,

Only the year before, Rutherford and his collaborators had established experimentally that the consists of a heavy positively charged nucleus with substantially lighter negatively charged circling around it at considerable distance. According to classical physics, such a system would be unstable, and Bohr felt compelled to postulate, in a trilogy of articles published in The Philosophical Magazine in 1913, that electrons could only occupy particular orbits determined by the quantum of action and that from an atom occurred only when an electron jumped to a lower-energy,

Although radical and unacceptable to most physicists at the time, the was able to account for an ever-increasing number of experimental data, famously starting with the emitted by, In the spring of 1916, Bohr was offered a new professorship at the University of Copenhagen; dedicated to theoretical physics, it was the second professorship in physics there.

As physics was still pursued in the cramped quarters of the Polytechnic Institute, it is not surprising that already in the spring of 1917 Bohr wrote a long letter to his asking for the establishment of an Institute for Theoretical Physics. In the inauguration speech for his new institute on March 3, 1921, he stressed, first, that experiments and experimenters were indispensable at an institute for theoretical physics in order to test the statements of the theorists.

Second, he expressed his ambition to make the new institute a place where the younger generation of physicists could propose fresh ideas. Starting out with a small staff, Bohr’s institute soon accomplished those goals to the highest degree. Get a Britannica Premium subscription and gain access to exclusive content.

1. Already in his 1913 trilogy, Bohr had sought to apply his theory to the understanding of the of elements.
2. He improved upon that aspect of his work into the early 1920s, by which time he had developed an scheme building up the periodic table by adding electrons one after another to the atom according to his,

When Bohr was awarded the Nobel Prize for his work in 1922, the Hungarian physical chemist, together with the physicist Dirk Coster from Holland, were working at Bohr’s institute to establish experimentally that the as-yet-undiscovered atomic element 72 would behave as predicted by Bohr’s theory.

#### When was modern periodic table discovered?

Development of the periodic table Dmitri Mendeleev. Reproduced courtesy of the Library and Information Centre, Royal Society of Chemistry. As we have seen, Mendeleev was not the first to attempt to find order within the elements, but it is his attempt that was so successful that it now forms the basis of the modern periodic table.

• Mendeleev did not have the easiest of starts in life.
• He was born at Tobolsk in 1834, the youngest child of a large Siberian family.
• His father died while he was young, and so his mother moved the family 1500 km to St.
• Petersburg, where she managed to get Dmitri into a “good school”, recognising his potential.

In his adult life he was a brilliant scientist, rising quickly in academic circles. He wrote a textbook, Chemical Principles, because he couldn’t find an adequate Russian book. Mendeleev discovered the periodic table (or Periodic System, as he called it) while attempting to organise the elements in February of 1869.

He did so by writing the properties of the elements on pieces of card and arranging and rearranging them until he realised that, by putting them in order of increasing atomic weight, certain types of element regularly occurred. For example, a reactive non-metal was directly followed by a very reactive light metal and then a less reactive light metal.

Initially, the table had similar elements in horizontal rows, but he soon changed them to fit in vertical columns, as we see today. Not only did Mendeleev arrange the elements in the correct way, but if an element appeared to be in the wrong place due to its atomic weight, he moved it to where it fitted with the pattern he had discovered.

• For example, iodine and tellurium should be the other way around, based on atomic weights, but Mendeleev saw that iodine was very similar to the rest of the halogens (fluorine, chlorine, bromine), and tellurium similar to the group 6 elements (oxygen, sulphur, selenium), so he swapped them over.
• The real genius of Mendeleev’s achievement was to leave gaps for undiscovered elements.

He even predicted the properties of five of these elements and their compounds. And over the next 15 years, three of these elements were discovered and Mendeleev’s predictions shown to be incredibly accurate. The table below shows the example of Gallium, which Mendeleev called eka-aluminium, because it was the element after aluminium.

• Scandium and Germanium were the other two elements discovered by 1886, and helped to cement the reputation of Mendeleev’s periodic table.
• The final triumph of Mendeleev’s work was slightly unexpected.
• The discovery of the noble gases during the 1890s by William Ramsay initially seemed to contradict Mendeleev’s work, until he realised that actually they were further proof of his system, fitting in as the final group on his table.
You might be interested:  Goghat To Howrah Train Time Table

This gave the table the periodicity of 8 which we know, rather than 7 as it had previously been. Mendeleev never received a Nobel Prize for his work, but element 101 was named Mendelevium after him, an even rarer distinction.

 Eka-aluminium (Ea) Gallium (Ga) Atomic weight About 68 69.72 Density of solid 6.0 g/cm³ 5.9 g/cm³ Melting point Low 29.78°C Valency 3 3 Method of discovery Probably from its spectrum Spectroscopically Oxide Formula Ea 2 O 3, density 5.5 g/cm 3, Soluble in both acids and alkalis Formula Ga 2 O 3, density 5.88 g/cm 3, Soluble in both acids and alkalis

A comparison of Mendeleev’s predicted “Eka-aluminium” and Gallium, discovered by Paul Emile Lecoq in 1875

 A commemorative stamp showing Mendeleev and some of his original notes about the Periodic Table

Development of the periodic table

## What did Ernest Rutherford discover?

Work – The discovery of radioactivity in 1896 led to a series of more in-depth investigations. In 1899 Ernest Rutherford demonstrated that there were at least two distinct types of radiation: alpha radiation and beta radiation. He discovered that radioactive preparations gave rise to the formation of gases.

Working with Frederick Soddy, Rutherford advanced the hypothesis that helium gas could be formed from radioactive substances. In 1902 they formulated a revolutionary theory: that elements could disintegrate and be transformed into other elements. Back to top Back To Top Takes users back to the top of the page This year’s Nobel Prize announcements will take place 2–9 October.

All announcements will be streamed live here on nobelprize.org. See the full schedule Select the category or categories you would like to filter by Select the category or categories you would like to filter by Physics Chemistry Medicine Literature Peace Economic Sciences Decrease the year by one Choose a year you would like to search in Increase the year by one

#### What did Mendeleev and Moseley discover?

The Periodic Law – When Mendeleev put his periodic table together, nobody knew about the existence of the nucleus. It was not until 1911 that Rutherford conducted his gold foil experiment that demonstrated the presence of the nucleus in the atom. Just two years later, in 1913, English physicist Henry Moseley (1887-1915) examined x-ray spectra of a number of chemical elements.

• He would shoot x-rays through crystals of the element and study the wavelengths of the radiation that he detected.
• Moseley found that there was a relationship between wavelength and atomic number.
• His results led to the definition of atomic number as the number of protons contained in the nucleus of each atom.

He then realized that the elements of the periodic table should be arranged in order of increasing atomic number, rather than increasing atomic mass. Figure \(\PageIndex \) (Credit: User:Cepheus/Wikimedia Commons; Source: Commons Wikimedia, Periodic Table(opens in new window) ; License: Public Domain) When ordered by atomic number, the discrepancies within Mendeleev’s table disappeared. Tellurium has an atomic number of 52, while iodine has an atomic number of 53.

1. So even though tellurium does indeed have a greater atomic mass than iodine, it is properly placed before iodine in the periodic table.
2. Mendeleev and Moseley are credited with being most responsible for the modern periodic law : When elements are arranged in order of increasing atomic number, there is a periodic repetition of their chemical and physical properties.

The result is the periodic table as we know it today. Each new horizontal row of the periodic table corresponds to the beginning of a new period because a new principal energy level is being filled with electrons. Elements with similar chemical properties appear at regular intervals, within the vertical columns called groups,

#### Was modern periodic table discovered by Moseley?

The correct answer is Henry Moseley. The Modern periodic law & table was invented by Henry Moseley in 1913.

### Who is Mendeleev and Moseley?

The Periodic Law – When Mendeleev put his periodic table together, nobody knew about the existence of the nucleus. It was not until 1911 that Rutherford conducted his gold foil experiment that demonstrated the presence of the nucleus in the atom. Just two years later, in 1913, English physicist Henry Moseley (1887-1915) examined x-ray spectra of a number of chemical elements.

He would shoot x-rays through crystals of the element and study the wavelengths of the radiation that he detected. Moseley found that there was a relationship between wavelength and atomic number. His results led to the definition of atomic number as the number of protons contained in the nucleus of each atom.

He then realized that the elements of the periodic table should be arranged in order of increasing atomic number, rather than increasing atomic mass. Figure \(\PageIndex \) (Credit: User:Cepheus/Wikimedia Commons; Source: Commons Wikimedia, Periodic Table(opens in new window) ; License: Public Domain) When ordered by atomic number, the discrepancies within Mendeleev’s table disappeared. Tellurium has an atomic number of 52, while iodine has an atomic number of 53.

• So even though tellurium does indeed have a greater atomic mass than iodine, it is properly placed before iodine in the periodic table.
• Mendeleev and Moseley are credited with being most responsible for the modern periodic law : When elements are arranged in order of increasing atomic number, there is a periodic repetition of their chemical and physical properties.

The result is the periodic table as we know it today. Each new horizontal row of the periodic table corresponds to the beginning of a new period because a new principal energy level is being filled with electrons. Elements with similar chemical properties appear at regular intervals, within the vertical columns called groups,

## What is Moseley’s periodic law?

Moseley’s law states that the square root of the frequency of the emitted x-ray is proportional to the atomic number. Importance of Moseley’s law: Using this law Moseley arranged K and Ar, Ni and CO in a proper way in Mendeleev’s periodic table.