CAN ANYONE GIVE ME ALL DRAWBACKS AND CONTRIBUTION OF DOBEREIGNER , NEWLAND AND MENDELEEV . I WILL MARK BRAINLIEST PLUS GIVE ALL MY POINTS . BUT I NEED BOTH DRAWBACKS AND CONTRIBUTION OF ALL PERSONS ..
Answers
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doberiener~
•Contribution- he was one of the first ones to classify the elements. He classified his elements into a group of three elements where the atomic mass of the middle element was approximately the arithmetic mean of the first and the last element.
•Drawback- his classification was not helpful as the atomic mass of the middle element was always not found to be correct.
Newland~
•Contribution- Newland arranged the elements in such a way where the properties of the first element was similar to that of the element. he used this law as that of the octave (music thing)
• Drawback- Only 56 elements were known at that time and he stated that no other elements would be further discovered. As we all know he was very wrong with his assumption.
He could only accommodate the elements which were lighter that was only till calcium.
Mendeleev~
•Contribution- His classification was one of the very useful classification of his time. His periodic law states that the elements are the periodic function of their atomic numbers. Some of the elements which he has arranged according to their atomic numbers was useful as the modern periodic table was arranged according to increasing atomic number.
•Drawbacks-
Anamalous pairs
Position of hydrogen
Position of isotopes
hope it was helpful :)