Multiple Choice
Why did Mendeleev switch the order of some elements in his periodic table, even though it contradicted their increasing atomic masses?
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2. Atoms & Elements
Periodic Table: Classifications
Multiple Choice
Why was Newlands' periodic table ultimately rejected by the scientific community?
A
It included noble gases, which had not yet been discovered.
B
It grouped elements with dissimilar properties together due to strict adherence to the Law of Octaves.
C
It successfully predicted the existence of undiscovered elements.
D
It was based on atomic number rather than atomic mass.
Verified step by step guidance1
Understand the historical context: Newlands proposed the Law of Octaves, arranging elements in order of increasing atomic mass and noticing that every eighth element had similar properties.
Recognize the key limitation: Newlands' periodic table strictly followed the Law of Octaves, which forced elements into groups even when their chemical properties did not match well.
Identify the main criticism: Because of this strict pattern, elements with dissimilar properties were grouped together, which contradicted the observed chemical behavior of elements.
Note that noble gases were not included in Newlands' table because they had not yet been discovered, so this was not a reason for rejection.
Understand that the periodic table based on atomic number, rather than atomic mass, was developed later and was not part of Newlands' approach.
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