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Modern Periodic Table

Chapter 7: Modern Periodic Table

10 solved questions

How the atomic size vary in a group and across a period? Explain with suitable example. Answer: Atomic size increases down a group and decreases from left to right across a period. Down a group: each new element has one more she... Modern Periodic Table 1 answer
Define ionization enthalpy. Name the factors on which ionisation enthalpy depends? How does it vary down the group and across a period? Variation of ionization energy down the group: On moving down the group, the ionization enthalpy decreases. This is because the electron is... Modern Periodic Table 2 answers
What are the valence electrons ? For s-block and p-block elements show that number of valence electrons is equal to its group number. Electrons present in the outermost shell of the atom of an element are called valence electrons. 3Li is an s-block element and its electroni... Modern Periodic Table 1 answer
Compare chemical properties of metals and non metals. The difference in chemical properties between metals and nonmetals. Nonmetals Metals 1. Nonmetals form acidic or neutral oxides when they re... Modern Periodic Table 1 answer
Explain : electronegativity and electron gain enthalpy. Which of the two can be measured experimentally? The ability of a covalently bonded atom to attract the shared electrons toward itself is called electronegativity (EN). Electronegativity ca... Modern Periodic Table 1 answer
Why the elements belonging to the same group do have similar chemical properties ? Chemical properties of elements depend upon their valency.Elements belonging to the same group have the same valency. Hence, the elements be... Modern Periodic Table 1 answer
Why the second ionization enthalpy is greater than the first ionization enthalpy ? The second ionization enthalpy (Δ_iH₂) is greater than the first ionization enthalpy (Δ_iH₁) as it involves removal of electron from the pos... Modern Periodic Table 1 answer
Explain the screening effect with a suitable example. In a multi-electron atom, the electrons in the inner shells tend to prevent the attractive influence of the nucleus from reaching the outerm... Modern Periodic Table 1 answer
Ionization enthalpy of Li is 520 kJ mol-1 while that of F is 1681 kJ mol-1. Explain. Both Li and F belong to period 2. Across a period, the screening effect is the same while the effective nuclear charge increases. As a resul... Modern Periodic Table 1 answer
La belongs to group 3 while Hg belongs to group 12 and both belong to period 6 of the periodic table. La and Hg both belong to period 6. Therefore, n = 6. Elements of group 3 to group 12 belong to the d-block of the modern periodic table. The... Modern Periodic Table 1 answer