The modern periodic table arranges elements in order of increasing:
A. Number of neutrons
B. Mass number
C. Atomic number
D. Atomic mass
Answer: Option C
Solution (By JKSSB Mock Tests)
The modern periodic law, established by Henry Moseley, states that the properties of elements are periodic functions of their atomic numbers. Mendeleev’s original table was based on atomic mass, but the modern version uses atomic number which resolves anomalies like Ar (Z=18, mass 40) and K (Z=19, mass 39).
Explanation:
Finely divided nickel is used as catalyst for hydrogenation of unsaturated oils to saturated fats. Platinum and palladium can also be used but are more expensive. The reaction occurs at about 150°C with H₂ gas. Nickel catalyst is prepared by reducing NiO with H₂. This is an important industrial process for making margarine and shortenings.
Explanation:
Mendeleev arranged elements in order of increasing atomic mass, grouping those with similar properties. He left gaps for undiscovered elements. Modern table uses atomic number.
Explanation:
Graphite conducts electricity due to delocalized electrons in its structure and is chemically inert, allowing its use in electrodes for electrolysis and batteries. Diamond is an insulator. Hardness is not the reason; graphite is soft. It is opaque and black. Graphite electrodes are used in arc furnaces.
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