Chapter 5
āĻ āϧ্āϝাāϝ় ā§Ģ
Periodic Classification of Elements
āĻŽৌāϞ⧰ āϏāĻŽāϝ়ে āϏāĻŽāϝ়ে āĻļ্ā§°েāĻŖীāĻŦিāĻাāĻāύ
EXERCISES
āĻŦ্ā§াā§াāĻŽ
1. Which of the following statements is not a correct statement about the trends when going from left to right across the periods of periodic Table.
ā§§) āĻĒā§°্āϝাāĻŦৃāϤ্āϤ āϤাāϞিāĻাā§° āϏāĻŽāϝ়āĻোā§ąাā§° āĻŽাāĻেā§°ে āĻŦাāĻঁāĻĢাāϞ⧰ āĻĒā§°া āϏোঁāĻĢাāϞāϞৈ āϝোā§ąাā§° āϏāĻŽāϝ়āϤ āϧাā§°াāϏāĻŽূāĻšā§° āĻŦিāώāϝ়ে āϤāϞ⧰ āĻোāύāĻো āĻāĻ্āϤি āĻļুāĻĻ্āϧ āĻŦāĻ্āϤāĻŦ্āϝ āύāĻšāϝ়।
(āĻ) āĻŽৌāϞāĻŦোā§° āĻāĻŽ āϧাāϤুā§° āĻĒ্ā§°āĻৃāϤিā§° āĻšৈ āĻĒā§°ে।
(b) The number of valence electrons increases.
(āĻ) āĻ্āϝাāϞেāύ্āϏ āĻāϞেāĻ্āĻ্ā§°āύ⧰ āϏংāĻ্āϝা āĻŦৃāĻĻ্āϧি āĻĒাāϝ়।
Ans-
(c) The atoms lose their electrons more easily.
(āĻ) āĻĒā§°āĻŽাāĻŖুāĻŦোā§°ে āύিāĻā§° āĻāϞেāĻ্āĻ্ā§°āύāĻŦোā§° āĻ āϧিāĻ āϏāĻšāĻে āĻšেā§°ুā§ąাāĻ āĻĒেāϞাāϝ়।
(d) The oxides become more acidic.
(āĻ) āĻ āĻ্āϏাāĻāĻĄāĻŦোā§° āĻ āϧিāĻ āĻ āĻŽ্āϞীāϝ় āĻšৈ āĻĒā§°ে।
2. Element X forms a chloride with the formula XCL,, which is a solid with a high melting point. X would most likely be in the same group of the Periodic Table as
⧍) āĻŽৌāϞ X āϝ়ে XCL āϏূāϤ্ā§°ā§°ে āĻāĻা āĻ্āϞ⧰াāĻāĻĄ āĻāĻ āύ āĻā§°ে,, āϝিāĻো āĻāĻ্āĻ āĻāϞāύাংāĻāϝুāĻ্āϤ āĻāĻ িāύ āĻĒāĻĻাā§°্āĻĨ। X āϏāĻŽ্āĻā§ąāϤঃ āϏāĻŽāϝ়āϏূāĻী āϤাāϞিāĻাā§° āĻāĻেāĻা āĻোāĻāϤে āĻĨাāĻিāĻŦ
3. Which element has
ā§Š/ āĻোāύāĻো āĻŽৌāϞ⧰ āĻāĻে
(āĻ) āĻĻুāĻা āĻোāϞা, āϝি āĻĻুāϝ়োāĻা āϏāĻŽ্āĻĒূā§°্āĻŖ āĻāϞেāĻ্āĻ্ā§°āύেā§°ে āĻā§°ি āĻāĻে?
Ans-
(b) the electronic configuration 2, 8, 2?
(āĻ) āĻāϞেāĻ্āĻ্ā§°āύিāĻ āĻāύāĻĢিāĻাā§°েāĻāύ ⧍, ā§Ž, ⧍?
(c) a total of three shells, with four electrons in its valence shell?
(āĻ) āĻŽুāĻ āϤিāύিāĻা āĻā§ąā§°āĻŖ, āĻāϝ়াā§° āĻ্āϝাāϞেāύ্āϏ āĻā§ąā§°āĻŖāϤ āĻাā§°িāĻা āĻāϞেāĻ্āĻ্ā§°āύ āĻĨাāĻে?
(d) a total of two shells, with three electrons in its valence shell?
(āĻ) āĻŽুāĻ āĻĻুāĻা āĻā§ąā§°āĻŖ, āĻāϝ়াā§° āĻ্āϝাāϞেāύ্āϏ āĻā§ąā§°āĻŖāϤ āϤিāύিāĻা āĻāϞেāĻ্āĻ্ā§°āύ āĻĨাāĻে?
Ans-
(e) twice as many electrons in its second shell as in its first shell?
(āĻ) āĻāϝ়াā§° āĻĻ্āĻŦিāϤীāϝ় āĻā§ąā§°āĻŖāϤ āĻāϝ়াā§° āĻĒ্ā§°āĻĨāĻŽ āĻā§ąā§°āĻŖāϤāĻৈ āĻĻুāĻুāĻŖ āĻŦেāĻি āĻāϞেāĻ্āĻ্ā§°āύ?
4. (a) What property do all elements in the same column of the Periodic Table as boron have in common?
ā§Ē) (āĻ) āĻŦ’ā§°āĻŖā§° āϏৈāϤে āĻĒā§°্āϝাāĻŦৃāϤ্āϤ āϤাāϞিāĻাā§° āĻāĻেāĻা āϏ্āϤāĻŽ্āĻā§° āϏāĻāϞো āĻŽৌāϞ⧰ āĻŽাāĻāϤ āĻি āĻি āĻŦৈāĻļিāώ্āĻ্āϝ āĻāĻে?
(b) What property do all elements in the same column of the Periodic Table as fluorine have in common?
(āĻ) āĻĢ্āϞ’ā§°িāύ⧰ āϏৈāϤে āĻĒā§°্āϝাāĻŦৃāϤ্āϤ āϤাāϞিāĻাā§° āĻāĻেāĻা āϏ্āϤāĻŽ্āĻā§° āϏāĻāϞো āĻŽৌāϞ⧰ āĻŽাāĻāϤ āĻি āϧ⧰āĻŖā§° āĻŽিāϞ āĻāĻে?
5. An atom has electronic configuration 2, 8, 7.
ā§Ģ) āĻāĻা āĻĒā§°āĻŽাāĻŖুā§° āĻāϞেāĻ্āĻ্ā§°āύিāĻ āĻŦিāύ্āϝাāϏ ⧍, ā§Ž, ā§ āĻĨাāĻে।
(āĻ) āĻāĻ āĻŽৌāϞāĻোā§° āĻĒাā§°āĻŽাāĻŖā§ąিāĻ āϏংāĻ্āϝা āĻিāĻŽাāύ?
(b) To which of the following elements would it be chemically similar? (Atomic numbers are given in parentheses.)
(āĻ) āϤāϞ⧰ āĻোāύāĻো āĻŽৌāϞ⧰ āϏৈāϤে āĻ ā§°াāϏাāϝ়āύিāĻāĻাā§ąে āĻŽিāϞ āĻš’āĻŦ? (āĻĒā§°āĻŽাāĻŖু āϏংāĻ্āϝা āĻŦāύ্āϧāύীāϤ āĻĻিāϝ়া āĻšৈāĻে।)
N(7)
Ans-
6. The position of three elements A, B and C in the Periodic Table are shown below
ā§Ŧ) āĻĒā§°্āϝাāĻŦৃāϤ্āϤ āϤাāϞিāĻাāϤ āϤিāύিāĻা āĻŽৌāϞ A, B āĻā§°ু C ā§° āĻ ā§ąāϏ্āĻĨাāύ āϤāϞāϤ āĻĻেāĻুāĻā§ąা āĻšৈāĻে
Group 16 Group 17
(āĻ্ā§°ুāĻĒ ā§§ā§Ŧ) (āĻ্ā§°ুāĻĒ ā§§ā§)
- A
B C
(āĻ) A āĻāĻা āϧাāϤু āύে āĻ āϧাāϤু āϏেāĻāĻো āĻোā§ąা।
(b) State whether C is more reactive or less reactive than A.
(āĻ) C A āϤāĻৈ āĻ āϧিāĻ āĻĒ্ā§°āϤিāĻ্ā§°িāϝ়াāĻļীāϞ āύে āĻāĻŽ āĻĒ্ā§°āϤিāĻ্ā§°িāϝ়াāĻļীāϞ āϏেāĻāĻো āĻোā§ąা।
(c) Will C be larger or smaller in size than B?
(āĻ) āĻāϤāĻৈ āĻāĻাā§° āĻĄাāĻā§° āĻš’āĻŦ āύে āϏ⧰ু āĻš’āĻŦ?
(d) Which type of ion, cation or anion, will be formed by element A?
(āĻ) A āĻŽৌāϞ⧰ āĻĻ্āĻŦাā§°া āĻোāύāĻŦিāϧ āĻāϝ়āύ, āĻেāĻিāϝ়āύ āĻŦা āĻāύিāϝ়āύ āĻāĻ āύ āĻš’āĻŦ?
7. Nitrogen (atomic number 7) and phosphorus (atomic number 15) belong to group 15 of the Periodic Table. Write the electronic configuration of these two elements. Which of these will be more electronegative? Why?
ā§) āύাāĻāĻ্ā§°’āĻেāύ (āĻĒā§°āĻŽাāĻŖু āϏংāĻ্āϝা ā§) āĻā§°ু āĻĢāĻāĻĢā§°াāĻ (āĻĒā§°āĻŽাāĻŖু āϏংāĻ্āϝা ā§§ā§Ģ) āĻĒā§°্āϝাāĻŦৃāϤ্āϤ āϤাāϞিāĻাā§° ā§§ā§Ģ āύং āĻোāĻā§° āĻ āύ্āϤ⧰্āĻāϤ। āĻāĻ āĻĻুāĻা āĻŽৌāϞ⧰ āĻāϞেāĻ্āĻ্ā§°āύিāĻ āĻāύāĻĢিāĻাā§°েāĻāύ āϞিāĻা। āĻāϝ়াā§°ে āĻোāύāĻো āĻŦেāĻি āĻāϞেāĻ্āĻ্ā§°’āύেāĻেāĻিāĻ āĻš’āĻŦ? āĻিā§?
8. How does the electronic configuration of an atom relate to its position in the Modern Periodic Table?
ā§Ž) āĻāϧুāύিāĻ āĻĒā§°্āϝাāĻŦৃāϤ্āϤ āϤাāϞিāĻাāϤ āĻĒā§°āĻŽাāĻŖুā§° āĻāϞেāĻ্āĻ্ā§°āύিāĻ āĻŦিāύ্āϝাāϏ⧰ āϏৈāϤে āĻāϝ়াā§° āĻ ā§ąāϏ্āĻĨাāύ⧰ āϏāĻŽ্āĻĒā§°্āĻ āĻেāύেāĻুā§ąা?
9. In the Modern Periodic Table, calcium (atomic number 20) is surrounded by elements with atomic numbers 12, 19, 21 and 38. Which of these have physical and chemical properties resembling calcium?
⧝) āĻāϧুāύিāĻ āĻĒā§°্āϝাāĻŦৃāϤ্āϤ āϤাāϞিāĻাāϤ āĻেāϞāĻিāϝ়াāĻŽ (āĻĒাā§°āĻŽাāĻŖā§ąিāĻ āϏংāĻ্āϝা ⧍ā§Ļ)āĻ ā§§ā§¨, ⧧⧝, ⧍⧧ āĻā§°ু ā§Šā§Ž āĻĒā§°āĻŽাāĻŖু āϏংāĻ্āϝাā§° āĻŽৌāϞ⧰ে āĻāĻুā§°ি āĻāĻে।āĻāϝ়াā§°ে āĻোāύāĻোā§° āĻৌāϤিāĻ āĻā§°ু ā§°াāϏাāϝ়āύিāĻ āϧ⧰্āĻŽ āĻেāϞāĻিāϝ়াāĻŽā§° āĻĻā§°ে?
10. Compare and contrast the arrangement of elements in Mendeleev's Periodic Table and the Modern Periodic Table.
ā§§ā§Ļ) āĻŽেāĻŖ্āĻĄেāϞিāĻā§° āĻĒā§°্āϝাāĻŦৃāϤ্āϤ āϤাāϞিāĻা āĻā§°ু āĻāϧুāύিāĻ āĻĒā§°্āϝাāĻŦৃāϤ্āϤ āϤাāϞিāĻাāϤ āĻĨāĻা āĻŽৌāϞāϏāĻŽূāĻšā§° āĻŦিāύ্āϝাāϏ⧰ āϤুāϞāύা āĻā§°ু āĻŦিāĻĒā§°ীāϤāϤা āĻā§°া।