CBSE Class 10 Chemistry Periodic Classification of Elements MCQs Set B

Question. Silicon is surrounded by the elements of atomic number 6, 13, 15 and 32 in the periodic table, then  
(a) the properties of the elements of atomic numbers 6 and 32 will be similar to silicon
(b) the properties of the elements of atomic numbers 13 and 15 will be similar to silicon
(c) the properties of the elements of atomic numbers 6 and 13 will be similar to silicon
(d) the properties of elements of atomic numbers 15 and 32 will be similar to silicon.

Answer : A

Question. Element M forms an ion, M ²⁺ and element X forms an ion, X ^2–. The electronic arrangements of these ions are shown as :  

Which of the following statements about the elements M and X is/are incorrect?
I. M is in group 2 and period 4 of the periodic table.
II. M is a non-metal and X is a metal.
III. X is in group 15 and period 2 of the periodic table.
IV. M and X form MX type compound.
V. On moving from M towards X in the periodic table, electronegativity decreases.
(a) II, III and V
(b) I and IV
(c) Only II
(d) II and III

Answer : A

Question. An element M forms an ion M –. The electronic configuration of this ion is (2,8). Which statement is true?   
(a) M is in Group VI and Period 2.
(b) M is Group VII and Period 2.
(c) M is in Group VII and Period 3.
(d) M is in Group VI and Period 3.

Answer : B

Question. It was assumed by Newlands that only  
(a) 56 elements existed in nature
(b) 57 elements existed in nature
(c) 59 elements existed in nature
(d) 63 elements existed in nature.

Answer : A

Question. Cl, Br and I is a Döberiener’s triad. If the atomic masses of Cl and I are 35.5 and 127 respectively then the atomic mass of Br is  
(a) 162.5
(b) 91.5
(c) 81.25
(d) 45.625

Answer : C

Question. Which of the following properties does not match elements of halogen family?  
(a) They have seven electrons in their valence shell.
(b) They are diatomic in their molecular form.
(c) They are highly reactive.
(d) They are metallic in nature.

Answer : D

Question. The ‘law of octaves’ was enunciated by   
(a) Lother Meyer
(b) Mendeleev
(c) Dobereiner
(d) Newlands.

Answer : D

Question. Moving down a group of the periodic table,    
(a) the number of valence electrons increases
(b) the metallic characteristics of the elements increases
(c) the ability of the elements to form positive ions decreases
(d) the atomic number of the elements decreases.

Answer : B

Question. Li, Na and K is a Dobereiner triad. The atomic masses of Li and K are 7 and 39 respectively. What is the expected mass of Na?  
(a) 7
(b) 18
(c) 23
(d) 39

Answer : C

Question. Considering the elements B, Al, Mg and K, the correct order of their metallic character is    
(a) B > Al > Mg > K
(b) Al > Mg > B > K
(c) Mg > Al > K > B
(d) K > Mg > Al > B

Answer : D

Question. In the third period of the periodic table, the element having smallest size is   
(a) Na
(b) Al
(c) Cl
(d) Si

Answer : C

Question. According to Mendeléev’s periodic law, the properties of elements are a periodic function of their  
(a) atomic numbers
(b) atomic masses
(c) atomic volumes
(d) atomic sizes.

Answer : B

Question. X, Y and Z are the three elements, each one belongs to any one of the groups IA, IIIA and VA.   
The oxide of X is amphoteric, the oxide of Y is highly acidic, and the oxide of Z is highly basic.
Identify the groups to which these elements X, Y and Z belong?
      X   Y   Z
(a) VA IA IIIA
(b) IA VA IIIA
(c) IIIA IA VA
(d) IIIA VA IA

Answer : D

Question. The elements with atomic number 3 to 10 belong to the second period. Identify the most electropositive and the most electronegative element respectively.  
(a) F, Li
(b) Li, F
(c) Li, Ne
(d) Ne, Li

Answer : B

Question. Which element has the largest size in the second period?   
(a) N
(b) F
(c) Li
(d) Be

Answer : C

Question. Study the given table carefully.  

Identify P, Q, R, T and U.
       P Q  R T  U
(a) Mg O Ne P Ar
(b) O Mg Ar P Ne
(c) Mg O Ar P Ne
(d) O Mg Ne P Ar

Answer : A

Question. State True (T) or False (F) for the given statements.   
(i) John Newlands, arranged the known elements in the order of increasing atomic numbers.
(ii) He started with the element having the lowest atomic mass (hydrogen) and ended at thorium which was the 56th element.
(iii) He found that every ninth element had properties similar to that of the first.
(iv) The properties of lithium and sodium were found to be the same.
(v) Beryllium and magnesium resemble each other.
(vi) Newlands’ law of octaves worked well with higher elements only.
(i) (ii) (iii) (iv) (v) (vi)
(a) F T F T T T
(b) T F T F T T
(c) T F F F T T
(d) F T F T T F

Answer : D

Question. The proton numbers of four elements are given below.  

Which of the following pairs of elements belong to the same group of the periodic table?
(a) W and X
(b) W and Y
(c) X and Z
(d) Y and Z

Answer : C

Question. An element X belongs to group 14^th and 2^nd period of the periodic table. Its atomic number will be   
(a) 6
(b) 14
(c) 7
(d) 15

Answer : A

Question. According to modern periodic law, the properties of elements are a periodic function of their  
(a) atomic masses
(b) atomic volumes
(c) atomic numbers
(d) densities.

Answer : C

Question. In the given metals one with the smallest size is   
(a) Rb
(b) Cs
(c) K
(d) Na

Answer : D

Question. Which of the following pairs of atomic numbers represents elements belonging to the same group?   
(a) 11 and 20
(b) 12 and 30
(c) 13 and 31
(d) 14 and 33

Answer : C

Question. Arrange the following atoms in the order of increasing atomic radius : F, Cl, C, O    
(a) F, Cl, O, C
(b) C, O, F, Cl
(c) O, C, F, Cl
(d) F, O, C, Cl

Answer : D

Question. The proton number of four elements are given below :  

Which of the following pairs of elements belong to the same period of the periodic table?
(a) W and X
(b) W and Y
(c) X and Y
(d) Y and Z

Answer : C

Question. Which of the following statements is not a correct statement about the trends when going from left to right across the periods of the periodic table?  
(a) The elements become less metallic in nature.
(b) The number of valence electrons increases.
(c) The atoms lose their electrons more easily.
(d) The oxides become more acidic.

Answer : C

Question. The given diagram shows the electron arrangement of two elements, A and B.   

Which of the following statements is correct about the two elements?
(i) A is a Period 3 element.
(ii) B is a Group III element.
(iii) Both A and B have strong metallic characteristics.
(iv) Both A and B from positive ions.
(a) (ii) only
(b) (i) and (ii) only
(c) (iii) and (iv) only
(d) (i), (ii), (iii) and (iv)

Answer : B

Question. Identify the pair of atomic numbers representing s-block elements.   
(a) 7, 15
(b) 9, 17
(c) 2, 10
(d) 11, 12

Answer : D

Question. The number of elements in the 5th period of periodic table are   
(a) 8
(b) 18
(c) 10
(d) 32

Answer : B

Question : Which one of the following elements exhibit the maximum number of valence electrons?
(a) Na
(b) Al
(c) Si
(d) P

Answer : D

Question : A liquid non-metal is ___________.
(a) phosphorous
(b) mercury
(c) bromine
(d) nitrogen

Answer : C

Question : New lands relation is called
(a) Musical Law
(b) Law of Octaves
(c) Periodic Law
(d) Atomic Mass Law

Answer :  B

Question : The first alkali metal is _________.
(a) hydrogen
(b) lithium
(c) sodium
(d) francium

Answer : B

Question : A purple coloured solid halogen is ________.
(a) chlorine
(b) bromine
(c) iodine
(d) astatine

Answer : C

Question : An element X has mass number 40 and contains 21 neutrons in its atom. To which group of the Periodic Table does it belong?
(a) Group 1
(b) Group 4
(c) Group 2
(d) Group 3

Answer :   A

Question : What is the basis of long form of the periodic table?
(a) Atomic mass
(b) Atomic number
(c) Atomic size
(d) Metallic and Non-metallic character

Answer :   B

Question : The property of an element in the periodic table depends on its, ________.
(a) atomic size
(b) atomic mass
(c) electronic configuration
(d) number of protons

Answer : C

Question : An element has configuration 2, 8, 1. It belongs to, _________.
(a) 1 group and 3rd period
(b) 3 group and 1st period
(c) 1 group and 8th period
(d) 17 group and 3rd period

Answer : A

Question : The non-metallic element present in the third period other than sulphur and chlorine is
(a) oxygen
(b) fluorine
(c) nitrogen
(d) phosphorus

Answer : D

Question : At the end of each period the valence shell is __________.
(a) incomplete
(b) half filled
(c) singly occupied
(d) completely filled

Answer : D

Question : The family of elements having seven electrons in the outermost shell is ______.
(a) alkali metals
(b) alkaline earth metals
(c) halogens
(d) noble gases

Answer : C

Question : Which of the following factors does not affect the metallic character of an element?
(a) Atomic size
(b) Ionisation potential
(c) Electronegativity
(d) Atomic radius

Answer : C

Question : The family of elements to which potassium belongs is _________.
(a) alkali metals
(b) alkaline earth metals
(c) halogens
(d) noble gases

Answer : A

Question : The modern periodic table is given by ________
(a) Mendeleev
(b) Einstein
(c) Bohr
(d) Mosley

Answer: D

Question : Elements belonging to groups 1 to 17 are called __________.
(a) noble gases
(b) normal elements
(c) transition elements
(d) inner transition elements

Answer : B

Question : The number of electrons in the valence shell is equal to its ________.
(a) atomic mass
(b) group number
(c) period number
(d) atomic volume

Answer : B 

Question : Lanthanides and actinides are also called ___________.
(a) normal elements
(b) transition elements
(c) noble gases
(d) inner transition elements

Answer : D

Question : The non-metals are present:
(a) On the right hand side of the periodic table.
(b) In the middle of the periodic table.
(c) In the centre of the periodic table.
(d) On the left hand side of the periodic table.

Answer :  A

Question : The family of elements to which calcium belongs is __________.
(a) alkali metals
(b) alkaline earth metals
(c) halogens
(d) noble gases

Answer : B

Question : The least reactive element in group 17 is ___________.
(a) fluorine
(b) chlorine
(c) bromine
(d) iodine

Answer : D

Assertion & Reasoning Based MCQs

(a) Both assertion and reason are true, and reason is correct explanation of the assertion.
(b) Both assertion and reason are true, but reason is not the correct explanation of the assertion.
(c) Assertion is true, but reason is false.
(d) Assertion is false, but reason is true.

Question. Assertion : According to Mendeleev’s periodic law, the properties of elements is the periodic function of their atomic numbers.  
Reason : Mendeleev placed some elements with higher atomic mass before the elements with lower atomic mass.

Answer : D

Question. Assertion : Number of valence electrons decreases down the group.   
Reason : Number of valence electrons increases when we move left to right in a period.

Answer : D

Question. Assertion : Group18 is placed at the extreme right of the periodic table.   
Reason : It is in accordance with their electronic configuration.

Answer : A

Question. Assertion : In Newlands’ octaves, the properties of lithium and sodium were found to be same.  
Reason : Sodium is the eighth element after lithium.

Answer : A

Question. Assertion : Atomic size of As is more than that of P.   
Reason : Atomic size decreases along a period.

Answer : B

Question. Assertion : Elements in the same vertical column have similar properties.   
Reason : Periodic properties of elements is a function of atomic number.

Answer : B

Question. Assertion : Atomic size of potassium is greater than that of sodium.    
Reason : As we go down the group, atomic radius increases.

Answer : A