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Question
Discuss and compare the trend in ionisation enthalpy of the elements of group1 with those of group17 elements.
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Solution
As we move across the periodic table the ionization energy increases because of the increase in the effective nuclear charge and decrease of the shielding effect as more and more electrons get added in the same orbital. Thus group 1 has lower ionization enthalpy compared to that of group 17 and also group 1 by losing one electron it will acquire the nearest noble gas electronic configuration which also contributes towards its lower ionization enthalpy.
Important Concepts Discussed in the Classification of Elements and Periodicity in Properties:
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Modern periodic law and the present form of the periodic table
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Nomenclature of elements with atomic numbers > 100 and why do we need to classify elements?
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Genesis of periodic classification
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Electronic configurations of elements and the periodic table
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Groupwise electronic configurations
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Electronic configurations and types of elements: s–, p–, d–, f– BLOCKS
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The s – block elements
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The p – block elements
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The d block elements
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The f block elements (inner-transition elements)
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Metals, non-metals, and metalloids
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Periodic trends in properties of elements
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Trends in physical properties
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Atomic radius
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Ionic radius
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Ionization enthalpy
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Electron gain enthalpy
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Electronegativity
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Periodic trends in chemical properties
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Periodicity of valence or oxidation states
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Anomalous properties of second-period elements
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Periodic trends and chemical reactivity
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