Which of the following is the contribution made by dobereiner?

Johann Wolfgang Döbereiner (13 December 1780 – 24 March 1849) was a German chemist who is best known for work that foreshadowed the periodic law for the chemical elements, and for inventing the first lighter, which was known as the Döbereiner’s lamp.

How did dobereiner and Mendeleev contribute to the periodic table?

From 1817 through the time of Mendeleev, many scientists made important contributions to what would become the modern periodic table. In 1817, Johann Dobereiner noticed that the atomic mass of strontium was halfway between those of calcium and barium. These three elements had similar properties.

What was his contribution to the periodic table of the elements?

Dmitri Mendeleev was a Russian chemist who lived from 1834 to 1907. He is considered to be the most important contributor to the development of the periodic table. His version of the periodic table organized elements into rows according to their atomic mass and into columns based on chemical and physical properties.

How many elements did Johann dobereiner discover?

three elements
In 1829, a German chemist, Johann Dobereiner (1780–1849), placed various groups of three elements into groups called triads. One such triad was lithium, sodium, and potassium. Triads were based on both physical as well as chemical properties.

What is the contribution of Newlands?

An English scientist called John Newlands put forward his Law of Octaves in 1864. He arranged all the elements known at the time into a table in order of relative atomic mass. When he did this, he found a pattern among the early elements.

What did Dechancourtois contribute to the periodic table?

Biography & Contributions De Chancourtois was the first to arrange the chemical elements in order of atomic weights. He devised an early form of periodic table, which he called the telluric helix because the element tellurium came in the middle.

Who gave the law of octave?

J.A.R. Newlands
Law of octaves, in chemistry, the generalization made by the English chemist J.A.R. Newlands in 1865 that, if the chemical elements are arranged according to increasing atomic weight, those with similar physical and chemical properties occur after each interval of seven elements.

When did Dobereiner come up with his periodic table?

Dobereiner’s Periodic Table. A German scientist called Johann Dobereiner put forward his law of triads in 1817. Each of Dobereiner’s triads was a group of three elements. The appearance and reactions of the elements in a triad were similar to each other.

When did Dobereiner come up with his law of triads?

A German scientist called Johann Dobereiner put forward his law of triads in 1817. Each of Dobereiner’s triads was a group of three elements. The appearance and reactions of the elements in a triad were similar to each other.

What did Dobereiner discover about the properties of bromine?

During the 1820 s Döbereiner’s experiments with the ignition of hydrogen on contact with powdered platinum led the Swedish chemist J.J. Berzelius to develop the concept of catalysis. Toward the end of the decade Döbereiner found that the properties of bromine, a liquid, seem halfway between those of chlorine gas and the solid iodine.

Who was involved in the development of the periodic table?

Between 1829 and 1858 a number of scientists (Jean Baptiste Dumas, Leopold Gmelin, Ernst Lenssen, Max von Pettenkofer, and J.P. Cooke) found that these types of chemical relationships extended beyond the triad. See also: Development of the Periodic Table, de Chancourtois , Dobereiner, Mendeleev, Moseley , Newlands, Seaborg