how were the elements,that were discovered later ,accomodated{placed} in the mendeleev 's periodic table
Answers
Answer:
Explanation:
Mendeleev's periodic table
Dmitri Mendeleev
Like many scientists working at the end of the 19th-century the Russian chemist Dmitri Mendeleev (1834-1907) was looking for ways to organise the known elements. Mendeleev published his first periodic table of the elements in 1869.
Features of Mendeleev's tables
Mendeleev arranged the elements in order of increasing relative atomic mass. When he did this he noted that the chemical properties of the elements and their compounds showed a periodic trend. He then arranged the elements by putting those with similar properties below each other into groups. To make his classification work Mendeleev made a few changes to his order:
he left gaps for yet to be discovered elements
he switched the order of a few elements to keep the groups consistent
Six rows, eight columns showing H, Li, Be, B, C, N, O, F. Na, Mg, Al, Si, P, S, Cl, K, Ca, Ti, V, Cr. Fe, Co, Ni and Cu. (Cu), Zn, As, So, B, Rb, Sr, Yt, Zr, Nb, Mo, Ru. Rh, Pd and Ag.
Mendeleev's periodic table
Predictions using gaps
Mendeleev left gaps in his table to place elements not known at the time. By looking at the chemical properties and physical properties of the elements next to a gap, he could also predict the properties of these undiscovered elements. For example, Mendeleev predicted the existence of 'eka-silicon', which would fit into a gap next to silicon. The element germanium was discovered later. Its properties were found to be similar to the predicted ones and confirmed Mendeleev's periodic table.
Pair reversals
Iodine has a lower relative atomic mass than tellurium. So iodine should be placed before tellurium in Mendeleev's tables. However, iodine has similar chemical properties to chlorine and bromine. To make iodine line up with chlorine and bromine in his table, Mendeleev swapped the positions of iodine and tellurium.
Answer:
Mendeleev wrote the atomic weight and the properties of each element on a card. ... When Mendeleev arranged the elements in order of increasing atomic mass, the properties where repeated. Because the properties repeated themselves regularly, or periodically, on his chart, the system became known as the periodic table.