Element are the fundamental building blocks that make up all of the material matter in our environment. Initially, 31 chemical elements were identified in 1800. In 1865, a few technological advances led to the discovery of around 63 more elements. As a result, the periodic classification of elements became necessary. Currently, 118 elements are known to us, and some of these chemical elements are artificial.
Download Class 11 Chemistry Worksheet on Chapter 3 Classification of Elements and Periodicity in Properties Set 1 PDF.
CBSE Class 11 Chemistry Chapter 3 Classification of Elements and Periodicity in Properties – Set 1
Q-1: What happens when a neutral atom is converted into an anion?
a) Atomic weight increases
b) Atomic weight decreases
c) Size increases
d) Size decreases
Q-2: The element with the highest affinity for electrons will belong to
a) Period 2, Group 17
b) Period 2, Group 18
c) Period 3, Group 17
d) Period 2, Group 1
Q-3: Which of the following is not a representative element?
a) Z = 38
b) Z = 31
c) Z = 54
d) Z = 26
Q-4: Find the incorrect statement.
a) For group 2, the valence electron and valency are identical.
b) Metal, non-metal, and metalloids are all present in P-block elements.
c) Helium (He) is the only noble gas with two valence electrons.
d) The smallest element on the periodic table is He.
Q-5: The symbol of an element with atomic number Z = 109 is
a) Unp
b) Uns
c) Uno
d) Une
Q-6: Which among the following will have the largest atomic radii based on their positions in the periodic table?
Be, N, O, Ne
Q-7: Is the electronegativity of an atom constant?
Q-8: Which element among the following has the highest positive electron gain enthalpy? Neon, Nitrogen, and Fluorine
Q-9: Give the inert gas atom’s name and atomic number in which the total number of d-electrons equals the difference in numbers of total p and s-electrons.
Q-10: Show by chemical reaction with water that K2O is a basic oxide and Cl2O7 is an acidic oxide.
Q-11: What would be the atomic number for the following if they were discovered in the future?
(i) Next alkali metal
(ii) Next alkaline earth metal
(iii) Next inert gas
Q-12: Give the general valence shell electronic configuration of transition elements and some characteristics. Also, tell the block to which they belong and why?
Q-13: Do the non-metallic character exhibited by the halogens have any relation to ionisation enthalpy?
Q-14: Why do s-block elements act as strong reducing agents?
Q-15: What will be the fluorine atom’s atomic radius in a covalently bound fluorine molecule with a 128 pm internuclear distance?
Q-16: Why are there only 14 lanthanides and only 14 actinides?
Q-17:
a) What do you understand by shielding effect or screening effect? How does it affect the ionisation enthalpy?
b) Why can Na not exhibit a +2 oxidation state?
Q-18: Li < Na < K < Rb < Cs are in increasing order of reactivity in group 1, while F > Cl > Br > I are in that group 17. Explain.
Q-19: What is the diagonal relationship? What are the main reasons for the anomalous behaviour of the elements belonging to the second period?
Q-20: The amount of energy released when 1 × 1010 atoms of bromine in vapour state are converted to Br– ions according to the equation, Br(g) + e– → Br–(g) is 60.90 × 10-10 J. Calculate the electron gain enthalpy of bromine atom in terms of eV per atom.
Download the PDF to access answers to the Chemistry Worksheet for Class 11 Chemistry Chapter 3 Classification of Elements and Periodicity in Properties Set – 1.
Read Also:
- Classification of Elements and Periodicity in Properties
- Periodic Classification of Elements
- Periodic Properties of Elements and Their Significance
- Periodic Table
- Modern Periodic Law
- Important Questions for Class 11 Chemistry Chapter 3 Classification of Elements and Periodicity in Properties
- Class 11 Chemistry Chapter 3 Classification of Elements and Periodicity in Properties
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