# Periodic Classification of Elements-Important Questions & Preparation Tips

In this article you will get the clue that from where and how the questions are being framed from the chapter Periodic Classification of Elements

Created On: Jun 6, 2013 12:51 IST
Modified On: Jun 6, 2015 17:54 IST

In this article you will get the clue that from where and how the questions are being framed from the chapter Periodic Classification of Elements
The experts of jagranjosh.com have full confidence that you will not miss any of the questions in the board exam as well as in competitive exams from this chapter if you will keep the following terms / question in your mind while studying

• Dobereiners law and  new lands law of octave
• Merits  and limitations of Mendeleev classification of elements
• What are metalloids?
• A, and B are 2 elements having similar properties which obey new lands law of octave. How many elements are there in between A and B?
• A, B and C are the elements of Dobereiner’s traid? If the atomic mass of A is 7 and that of C is 39, what should be the atomic mass of B?
• What is the significance of atomic number in the modern classification of elements? Explain with the help of example.
• Where hydrogen should be placed in modern periodic table? Give reason
• State the periodic law on which Mendeleev’s periodic table was based? Why and how was this periodic law changed?
• Would you place the two isotopes of chlorine, Cl-35 and Cl-37 in different slots because of their different atomic masses or in the same slot because their chemical properties are same? Explain?
• What are the characteristics of valence electron?
• How to find the group number and period number of any element?
• Carbon (atomic number 6) and silicon (atomic number 14) are elements in the same group of the periodic table. Give the electronic arrangements of the carbon and silicon atoms, and state the group in which these elements are present.
• Merits of the modern periodic table
• Elements X and Y belong to groups 1 and 17 of the periodic table respectively. What will be the nature of the bond in the compound XY?
• An element X is in group 13 of the periodic table. What is the formula of its oxide?
• Change of atomic radii while going in a periodic table from left to right
• Variation of valancy while moving top to bottom in the group
• Explain: do all the elements of group have similar chemical properties
• How do electro positive character of elements changes while going down in a group of a periodic table?
• Reason for not giving any fixed position to hydrogen in Mendeleev’s periodic table
• The atomic size gets decrease while moving left to right in the third period. Why?
• The chemical reactivity first decrease and then increases while moving left to right in the third period. Why?
• Variation in the atomic size, metallic character and chemical reactivity while moving from top to bottom with reason
• Zerovalent group

There are some sample questios given below :

1. Which of the following is not true for metalloids?
a. They are borderline elements that exhibit both metallic and non metallic properties to some extent.
b. They usually act as electron donors with non-metals and as electron acceptors with metals,
c.  Some of these elements are boron, silicon and germanium.
d. They are good conductors of heat and electricity.

2. Which of the following statement (s) about the Modern Periodic Table are incorrect
i. The elements in the Modern Periodic Table are arranged on the basis of their decreasing atomic number
ii. The elements in the Modern Periodic Table are arranged on the basis of their increasing atomic masses
iii. Isotopes are placed in adjoining group (s) in the Periodic Table
iv. The elements in the Modern Periodic Table are arranged on the basis of their increasing atomic number
a.  (i) only
b. (i), (ii) and (iii)
c.  (i), (ii) and (iv)
d. (iv) only

3. Which of the following is the correct order of decreasing first ionization energy:
a. C > B > Be > Li
b. C > Be > B > Li
c. B > C > Be > Li
d. Be > Li > B > C

4. The first ionization energy of an element is 736 kJ per mole of atoms. An atom of this element in the ground state has a total of how many valence electrons?
a. 1
b. 2
c. 3
d. 4

5. Arrange the following elements in the order of their increasing nonmetallic character: Li, O, C, Be, F
a. F < O < C < Be < Li
b.  Li < Be < C < O< F
c.  F < O < C < Be < Li
d. F < O < Be < C < Li

6. Six elements A, B, C, D, E and F have the following atomic numbers (A = 12, B = 17, C = 18, D = 7, E = 9 and F = 11). Among these elements, the element, which belongs to the 3rd period and has the highest ionization potential, is
a. A
b. B
c. C
d. F

7. Which of the following are the characteristics of isotopes of an element?
i.  Isotopes of an element have same atomic masses
ii. Isotopes of an element have same atomic number
iii. Isotopes of an element show same physical properties
iv. Isotopes of an element show same chemical properties
a. (i), (iii) and (iv)
b. (ii), (iii) and (iv)
c. (ii) and (iii)
d. (ii) and (iv)

8. Which of the following hydroxides is most basic?
a. Be(OH)2
b. Ba(OH)2
c. Ca(OH)2
d. Mg(OH) 2

9. The statement that is not true about electron affinity is
a.  It causes energy to be released
b. It causes energy to be absorbed
c. It is expressed in electron volts
d. It involves formation of an anion

10. Which of the following is Dobereiner’s triad?
a. Ne,Ca,Na
b. H2,N2, O2
c. Li, Na, K
d. Na, Br

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