What physical and chemical properties of elements were used by Mendeleev in creating his periodic table? List two observations which posed a challenge to Mendeleev's Periodic Law.
The physical property used by Mendeleev in creating his periodic table was the atomic mass of an element. Melting and boiling points were also used as physical characteristics.
The chemical property used by Mendeleev in creating his periodic table was the nature of oxide and hydride formed ( i.e. similarity in chemical properties were used by Mendeleev).
The two observations that challenged Mendeleev's Periodic Law were:
Arranging elements according to the increasing order of atomic mass could not be maintained. Chemical properties do not depend on atomic mass. Isotopes were not given any place in the table as they have different atomic mass but the same chemical properties.
Related Articles What were the criteria used by Mendeleev in creating his Periodic Table?
(a) State Mendeleev’s periodic law.(b) What chemical properties of elements were used by Mendeleev in creating his periodic table? (c) State any three limitations of Mendeleev’s classification of elements. (d) Besides gallium, which two other elements have since been discovered for which Mendeleev had left gaps in his periodic table ? (e) Which group of elements was missing from Mendeleev’s original periodic table?
Besides gallium, which other elements have since been discovered that were left by Mendeleev in his periodic table?
Why do we classify elements?What were the two criteria used by Mendeleev in creating his Periodic Table?Why did Mendeleev leave some gaps in his Periodic Table?In Mendeleev's Periodic Table, why was there no mention of Noble gases such as Helium, Neon and Argon?Would you place the two isotopes of chlorine, Cl-35 and Cl-37 in different slots because of their different atomic masses or in the same slot because their chemical properties are the same? Justify your answer.
(a) List any three observations which posed a challenge to Mendeleev’s Periodic law.(b) How does the metallic character of elements vary on moving from(i) left to right in a period,(ii) from top to bottom in a group of the Modem Periodic Table?Give a reason for your answer.
In Mendeleev's Periodic Table, gaps were left for the elements to be discovered later. Which of the following elements found a place in the Periodic Table later?ChlorineSiliconOxygenGermanium
(a) Why do we classify elements?(b) What were the two criteria used by Mendeleev to classify the elements in his periodic table? (c) Why did Mendeleev leave some gaps in his periodic table? (d) In Mendeleev’s periodic table, why was there no mention of noble gases like helium, neon and argon? (e) Would you place the two isotopes of chlorine, Cl-35 and Cl-37 in different slots because of their different atomic masses or in the same slot because their chemical properties are the same? Justify your answer.
Name two elements whose properties were predicted on the basis of their positions in Mendeleev’s periodic table.
The three elements predicted by Mendeleev from the gaps in his periodic table were known as eka-boron, eka – aluminium and eka-silicon. What names were given to these elements when they were discovered later on?
State the Periodic Law on which the Modern Periodic Table is based.
In the Modern Periodic Table, calcium (atomic number 20) is surrounded by elements with atomic number 12, 19, 21 and 38. Which of these have physical and chemical properties resembling calcium?
In Mendeleev’s periodic table, gaps were left for the elements to be discovered later. Which one of the following elements found a place in the periodic table later?GermaniumChlorineOxygenSilicon
Compare and contrast the arrangement of elements in Mendeleev’s Periodic Table and the Modern Periodic Table.
Mendeleev's basis for the Periodic Table is ____________.
In the modern periodic table, the element calcium (atomic number = 20) is surrounded by elements with atomic numbers 12, 19, 21, and 38. Which of these elements has physical and chemical properties resembling those of calcium and why?
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