Ncert – class 11- unit3- Classification of Elements and Periodicity in Properties Welcome to your Ncert - class 11- unit3- Classification of Elements and Periodicity in Properties 1. An element X has electronic configuration 2, 8, 2. It forms ionic compounds with ions like nitrate, sulphate and phosphate. What will be the formulae of these compounds? $$X_{2}NO_{3}, X SO_{4}, X (PO_{4})_{2}$$ $$X_{2}NO_{3}, X SO_{4}, X_{3}(PO_{4})_{2}$$ $$X_{2}NO_{3}, X_{2}SO_{4}, X_{2}(PO_{4})_{3}$$ $$X_{2}NO_{3}, X SO_{4}, X_{2}(PO_{4})_{3}$$ None 2. Name the element which has a total of three shells with five electrons in its valence shells: Nitogen Anitmony Arsenic Phosphorus None 3. The electron affinities of B,C, N and O are in the order of _____________. B < C < N < O B > C < O < N B N B O > N None 4. 'Electronic configuration' represents : arrangement of neutrons arrangement of electrons arrangement of electrons, protons and neutrons arrangement of protons None 5. The correct order of negative electron gain enthalpy is: 𝑂 < 𝐹 𝐶𝑙 < 𝐹 𝐹 < 𝐵 𝑟 𝑆 < 𝑂 None 6. Which of the following elements will gain one electron more readily in comparison to other elements of their group? 𝑂 ( 𝑔 ) 𝑁 ( 𝑔 ) 𝐶 𝑙 ( 𝑔 ) 𝑆 ( 𝑔 ) None 7. Assertion : Element number 12 and element number 20 undergo similar chemical reactionsReason : Element number 12and element number 20 have similar valence electron configuration Assertion is correct but reason is incorrect Both assertion and reason are correct and reason is the correct explanation for assertion Both assertion and reason are correct but reason is not the correct explanation for assertion Assertion is incorrect but reason is correct None 8. Which pair of elements has the same characteristic chemical properties? 𝑍 = 3 , 𝑍 = 11 Z=4,Z=24 Z=13,Z=22 𝑍 = 2 , 𝑍 = 4 None 9. Which statement is correct? The electron affinity of iodine is greater than bromine The electron affinity of bromine is less than chlorine The electron affinity of carbon is greater than oxygen The electron affinity of sulphur is less than oxygen None 10. Pick up the correct statement. Electron affinities of noble gases are high. Electron affinity of non - metals are low and those of metals are high Electron affinity of element having \(𝑑^{10}𝑠^{2}\)configuration is negative Electron affinity of fluorine is more than chlorine None 11. Within a period the elements having the lowest electron affinity are: group 1A alkali metals transition metals halogens actinides None 12. Increasing order of electron gain enthalpy is: Cl < N < O < Al O < N < Al < Cl N < O < Cl < Al Al < N < O < Cl None 13. In general, the properties that decrease and increase down a group in the periodic table, respectively, are: electronegativity and atomic radius. electron gain enthalpy and electronegativity electronegativity and electron gain enthalpy. atomic radius and electronegativity None 14. In 𝐹 and 𝐶𝑙 which one has higher electron affinity : 𝐶 𝑙 None of these Both have same F None 15. Classification of elements makes the study of physical and chemical properties of elements ________ and __________. simple, organised none of these slow, difficult Complicated, unorganized None 16. Which one the following arrangements represents the correct order of electron gain enthalpy (with negative sign) of given atomic species ? 𝑂 < 𝑆 < 𝐹 < 𝐶 𝑙 𝐶 𝑙 < 𝐹 < 𝑆 < 𝑂 𝐹 < 𝐶 𝑙 < 𝑂 < 𝑆 𝑆 < 𝑂 < 𝐶 𝑙 < 𝐹 None 17. In which pair do both atoms have one electron only in an "s" orbital in their ground states? 𝐻 , 𝐻 𝑒 𝐶 𝑢 , 𝐵 𝑒 𝐶𝑎 , 𝑆𝑐 𝐿 𝑖 , 𝐶 𝑟 None 18. Which one of the following statement is incorrect? Greater is the nuclear charge, greater is the electron gain enthalpy Nitrogen has almost zero electron gain enthalpy Electron gain enthalpy decrease from fluorine to iodine in the group Chlorine has highest electron gain enthalpy None 19. Regardless of its electron configuration, it must always be paramagnetic when it's a single, neutrally charged atom. Which of the following is this? Carbon Oxygen Neon Nitrogen None 20. Refer to changes in properties of elements on moving left to right across a period of the periodic table.For each property , choose the letter corresponding to the correct answer from A,B,C and D. The electron affinity of the elements in groups 1 to 7 : increases decreases goes up and down decreases and then increases None Time's up Please Share This Share this content Opens in a new window Opens in a new window Opens in a new window Opens in a new window Opens in a new window Opens in a new window Opens in a new window Opens in a new window Opens in a new window Opens in a new window Leave a Reply Cancel replyCommentEnter your name or username to commentEnter your email address to commentEnter your website URL (optional) Save my name, email, and website in this browser for the next time I comment.
