# data[].attributes.body
Name: Venkata Vaibhav Y.
Class: 10th F
Roll No: 33

# data[].attributes.body
Discovered in -7000 BCE

# data[].attributes.body
Discovered in -7000 BCE

# data[].attributes.body
Discovered in -7000 BCE

# data[].attributes.body
Discovered in -3000 BCE

# data[].attributes.body
Discovered in -3000 BCE

# data[].attributes.body
Discovered in -2500 BCE

# data[].attributes.body
Discovered in -2100 BCE

# data[].attributes.body
Discovered in -1600 BCE

# data[].attributes.body
Discovered in -1500 BCE

# data[].attributes.body
Discovered in -1000 BCE

# data[].attributes.body
Discovered in the year 1250

# data[].attributes.body
Discovered in the year 1669

# data[].attributes.body
Discovered in the year 1735

# data[].attributes.body
Discovered in the year 1735

# data[].attributes.body
Discovered in the year 1746

# data[].attributes.body
Discovered in the year 1751

# data[].attributes.body
Discovered in the year 1753

# data[].attributes.body
Discovered in the year 1755

# data[].attributes.body
Discovered in the year 1766

# data[].attributes.body
Discovered in the year 1771

# data[].attributes.body
Discovered in the year 1772

# data[].attributes.body
Discovered in the year 1774

# data[].attributes.body
Discovered in the year 1774

# data[].attributes.body
Discovered in the year 1781

# data[].attributes.body
Discovered in the year 1783

# data[].attributes.body
Discovered in the year 1783

# data[].attributes.body
Discovered in the year 1789

# data[].attributes.body
Discovered in the year 1789

# data[].attributes.body
Discovered in the year 1790

# data[].attributes.body
Discovered in the year 1791

# data[].attributes.body
Discovered in the year 1794

# data[].attributes.body
Discovered in the year 1797

# data[].attributes.body
Discovered in the year 1798

# data[].attributes.body
Discovered in the year 1801

# data[].attributes.body
Discovered in the year 1801

# data[].attributes.body
Discovered in the year 1802

# data[].attributes.body
Discovered in the year 1803

# data[].attributes.body
Discovered in the year 1803

# data[].attributes.body
Discovered in the year 1803

# data[].attributes.body
Discovered in the year 1803

# data[].attributes.body
Discovered in the year 1803

# data[].attributes.body
Discovered in the year 1807

# data[].attributes.body
Discovered in the year 1807

# data[].attributes.body
Discovered in the year 1808

# data[].attributes.body
Discovered in the year 1808

# data[].attributes.body
Discovered in the year 1808

# data[].attributes.body
Discovered in the year 1811

# data[].attributes.body
Discovered in the year 1817

# data[].attributes.body
Discovered in the year 1817

# data[].attributes.body
Discovered in the year 1817

# data[].attributes.body
Discovered in the year 1817

# data[].attributes.body
Discovered in the year 1825

# data[].attributes.body
Discovered in the year 1825

# data[].attributes.body
In the history of Periodic Table, Döbereiner's triads were an early attempt to sort the elements into some logical order by their physical properties. In 1817, a letter reported Johann Wolfgang Dobereiner's observations of the alkaline earths; namely, that strontium had properties that were intermediate to those of calcium and barium. By 1829, Döbereiner had found other groups of three elements (hence "triads") whose physical properties were similarly related. He also noted that some quantifiable properties of elements (e.g. atomic weight and density) in a triad followed a trend whereby the value of the middle element in the triad would be exactly or nearly predicted by taking the arithmetic mean of values for that property of the other two elements.

# data[].attributes.body
Discovered in the year 1829

# data[].attributes.body
Discovered in the year 1839

# data[].attributes.body
Discovered in the year 1843

# data[].attributes.body
Discovered in the year 1843

# data[].attributes.body
Discovered in the year 1844

# data[].attributes.body
Discovered in the year 1860

# data[].attributes.body
Discovered in the year 1861

# data[].attributes.body
Discovered in the year 1861

# data[].attributes.body
Discovered in the year 1863

# data[].attributes.body
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. Newlands was one of the first to detect a periodic pattern in the properties of the elements and anticipated later developments of the periodic law.

# data[].attributes.body
Working on the research done by Newlands, in 1869 a 35 year old Russian chemist named Dmitri Mendeleev presented a much bolder and more scientifically useful table of elements. In it, the periodic relationship between chemical groups is clearly illustrated. Mendeleev saw that there is a periodicity occurring in the physical and chemical properties, if the elements were arranged in order of their atomic weights. The periodic table gave order to the large amount of data available for all the elements. In Mendeleev's time there were about 60 to 70 known elements.

# data[].attributes.body
Discovered in the year 1875

# data[].attributes.body
Discovered in the year 1878

# data[].attributes.body
Discovered in the year 1878

# data[].attributes.body
Discovered in the year 1879

# data[].attributes.body
Discovered in the year 1879

# data[].attributes.body
Discovered in the year 1879

# data[].attributes.body
Discovered in the year 1880

# data[].attributes.body
Discovered in the year 1885

# data[].attributes.body
Discovered in the year 1885

# data[].attributes.body
Discovered in the year 1886

# data[].attributes.body
Discovered in the year 1886

# data[].attributes.body
Discovered in the year 1886

# data[].attributes.body
Discovered in the year 1894

# data[].attributes.body
Discovered in the year 1895

# data[].attributes.body
Discovered in the year 1898

# data[].attributes.body
Discovered in the year 1898

# data[].attributes.body
Discovered in the year 1898

# data[].attributes.body
Discovered in the year 1898

# data[].attributes.body
Discovered in the year 1898

# data[].attributes.body
Discovered in the year 1899

# data[].attributes.body
Discovered in the year 1899

# data[].attributes.body
Discovered in the year 1901

# data[].attributes.body
Discovered in the year 1907

# data[].attributes.body
Discovered in the year 1913

# data[].attributes.body
The popular periodic table layout, also known as the common or standard form (as shown at various other points in this article), is attributable to Horace Groves Deming. In 1923, Deming, an American chemist, published short (Mendeleev style) and medium (18-column) form periodic tables. Merck and Company prepared a handout form of Deming's 18-column medium table

# data[].attributes.body
Discovered in the year 1923

# data[].attributes.body
Discovered in the year 1925

# data[].attributes.body
Discovered in the year 1937

# data[].attributes.body
Discovered in the year 1939

# data[].attributes.body
Discovered in the year 1940

# data[].attributes.body
Discovered in the year 1940

# data[].attributes.body
Discovered in the year 1940

# data[].attributes.body
Discovered in the year 1944

# data[].attributes.body
Discovered in the year 1944