MCQs For Class 10 Science Chapter 5 Periodic Classification of Elements

Please refer to the MCQ Questions for Class 10 Science Chapter 5 Periodic Classification of Elements with Answers. The following Periodic Classification of Elements Class 10 Science MCQ Questions have been designed based on the current academic year syllabus and examination guidelines for Class 10. Our faculty has designed MCQ Questions for Class 10 Science with Answers for all chapters as per your NCERT Class 10 Science book.

Periodic Classification of Elements Class 10 MCQ Questions with Answers

Please see below Periodic Classification of Elements Class 10 Science MCQ Questions, solve the questions and compare your answers with the solutions provided below.

Question. If the two members of a Dobereiner triad are phosphorus and antimony, the third member of this triad is 
(1) Arsenic
(2) Sulphur
(3) Iodine
(4) Calcium

Question. Newlands could classify elements only upto – 
(1) Copper
(2) Chlorine
(3) Calcium
(4) Chromium

Question. From top to bottom in a group of the periodic table the electropositive character of the element 
(1) increases
(2) decreases
(3) remains unchanged
(4) changes irregularly

Question. The atoms of elements belonging to the same group of periodic table have same number of 
(1) protons
(2) electrons
(3) neutrons
(4) electrons in outermost shell

Question. The long form of periodic table consists of 
(1) seven periods and eight groups
(2) seven periods and eighteen groups
(3) eight periods and eighteen groups
(4) eighteen periods and eight groups

Question. Which of the following pair of atomic numbers represents elements in the same group ? 
(1) 11, 19
(2) 6, 12
(3) 4, 16
(4) 8, 17

Question. The group number and period number respectively of an element with atomic number 8 is 
(1) 6, 2
(2) 16, 2
(3) 6, 8
(4) 16, 4

Question. An atom has an electronic configuration 2, 8, 5. To which of the following elements would it be chemically similar ? 
(1) F (9)
(2) Na (11)
(3) N (7)
(4) Ar (18)

Question. All the elements in a period in the periodic table have the same 
(1) atomic number
(2) electronic configuration
(3) atomic weight
(4) valence shell

Question. All the members in a group of a long form of periodic table have the same 
(1) valency
(2) number of valence electrons
(3) chemical properties
(4) All of the above

Question. The electrons with atomic numbers 3, 11, 19, 37 and 55 belong to 
(1) alkali metals
(2) alkaline earth metals
(3) halogens
(4) noble gases

Question. An element X belongs to group 14 and 2nd period of the periodic table. Its atomic number will be 
(1) 6
(2) 14
(3) 7
(4) 15

Question. Which of the following elements is expected to show nonmetallic character ? 
(1) As
(2) Be
(3) B
(4) Br

Question: An element has 12 protons. The group and period to which this element belongs to is
(a) 2nd group, 3rd period
(b) 2nd group, 2nd period
(c) 3rd group, 2nd period
(d) 3rd group, 3rd period   

Question: The metal which is hard and has high melting point and used in filaments of electrical bulbs is
(a) Ni
(b) Fe
(c) Pt
(d) W   

Question: An element has atomic number 17. To which group, period does it belong ? It is metal or non-metal ?
(a) 7th group, 2nd period, Non-metal
(b) 17th group, 3rd period, Non-metal
(c) 7th group, 3rd period, Metal
(d) 17th group, 3rd period, Metal   

Question: Which of the following is correct order of size ?
(a) I+ > I > I–
(b) I– > I > I+
(c) I > I+ > I–
(d) I > I– > I+   

Question: The element which has least tendency to lose electron is
(a) H
(b) Li
(c) He
(d) Ne   

Question: Which of the following oxide is most basic?
(a) Li₂O
(b) Na₂O
(c) K₂O
(d) Cs₂O   

Question: Which of the following hydroxides is most basic?
(a) Be(OH)₂
(b) Ba(OH)₂
(c) Ca(OH)₂
(d) Mg(OH₂ 

Question: Which of the following is correct order of atomic size ?
(a) Cl < F < Br < I
(b) F < Cl < Br < I
(c) I < Br < Cl < F
(d) Br < I < Cl < F 

Question: The elements of group 16 are called
(a) Chalcogens
(b) Halogens
(c) Pnicogens
(d) Noble gases   

Question: Which of the following is correct order of atomic size ?
(a) Li < Na < K < Rb < Cs
(b) Li > Na > K > Rb > Cs
(c) Na < K < Li < Rb < Cs
(d) K < Na < Li < Rb < Cs   

Question: In Mendeleev’s Periodic Table, gaps were left for the elements to be discovered later.
Which of the following elements found a place in the periodic table later ? 
(a) Germanium
(b) Chlorine
(c) Oxygen
(d) Silicon     

Question: Which of the given elements A, B, C, D and E with atomic number 2, 3, 7, 10 and 30 respectively belong to the same period?
(a) Group 8
(b) Group 2
(c) Group 18
(d) Group 10 

Question: Upto which element, the Law of Octaves was found to be applicable
(a) Oxygen
(b) Calcium
(c) Cobalt
(d) Potassium   

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

Question: Which of the following gives the correct increasing order of the atomic radii of O, F and N ?
(a) O, F, N
(b) N, F, O
(c) O, N, F
(d) F, O, N   

Question: Which of the following is the outermost shell for elements of period 2 ? 
(a) K shell
(b) L shell
(c) M shell
(d) N shell 

Question: WTiich of the following elements does not lose an electron easily ?
(a) Na
(b) F
(c) Mg
(d) Al       

Question: Which of the following elements will form an acidic oxide ?
(a) An element with atomic number 7
(b) An element with atomic number 3
(c) An element with atomic number 12
(d) An element with atomic number 19       

Question: Which among the following elements has the largest atomic radii ?
(a) Na
(b) Mg
(c) K
(d) Ca 

Question: Which one of the following does not increase while moving down the group of the periodic table ?
(a) Atomic radius
(b) Metallic character
(c) Valence electrons
(d) Number of shells in an element   

Question: Which of the following is most reactive
(a) Li
(b) H
(c) Na
(d) K     

Question: The element with atomic number 14 is hard and forms acidic oxide and a covalent halide. To which of the following categories does the element belong?
(a) Metal
(b) Metalloid
(c) Non-metal
(d) Left-hand side element     

Question: Chlorine (17) belongs to which group and period
(a) 7, 3
(b) 17, 3
(c) 1, 3
(d) 16, 3 

Question: Which of the following is most reactive
(a) F₂
(b) Cl₂
(c) Br²
(d) I₂     

Question. Which of the following pair of atomic numbers represents s-block elements ? 
(1) 7, 15
(2) 6, 12
(3) 9, 17
(4) 3, 20

Question. In the periodic table, the element with atomic number 16 will be placed in the group   
(1) Fourteen
(2) Sixteen
(3) Thirteen
(4) Fifteen

Question. Which of the following statements about the Modern Periodic Table is correct ?
(a) It has 18 horizontal rows known as Periods.
(b) It has 7 vertical columns known as Periods.
(c) It has 18 vertical columns known as Groups.
(d) It has 7 horizontal rows known as Groups.

Question. Consider the following statements about an element ‘X‘ with number of protons 13.
(a) It forms amphoteric oxide
(B) Its valency is three
(C) The formula of its chloride is XC3
The correct statement (s) is/are
(A) only (A)
(B) only (B)
(C) (A) and (C)
(D) (A), (B) and (C)

Question. Arrange the following elements in the order of their decreasing metallic character Na, Si, Cl, Mg, Al :
(a) Cl > Si > Al > Mg > Na
(b) Na > Mg > Al > Si > Cl
(c) Na > Al > Mg >Cl > Si
(d) Al > Na > Si > Ca > Mg

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

Question. An element ‘X’ is forming an acidic oxide. Its position in modern periodic table will be
(a) Group 1 and Period 3
(b) Group 2 and Period 3
(c) Group 13 and Period 3
(d) Group 16 and Period 3

Question. A liquid non-metal is ……………
(a) phosphorous
(b) mercury
(c) bromine
(d) nitrogens.

Question. Which of the following elements will form an acidic oxide ?
(a) An element with atomic number 7.
(b) An element with atomic number 3.
(c) An element with atomic number 12.
(d) An element with atomic number 19.

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 ?   
(1) The elements become less metallic in nature
(2) The number of valence electrons increases
(3) The atoms lose their electrons more easily
(4) The oxides become more acidic

Question. Which of the following remains unchanged on going down the group in the periodic table ?   
(1) Valence electrons
(2) Atomic size
(3) Density
(4) Metallic character

Question. Which statement is wrong about C and Si ? 
(1) They have similar chemical properties
(2) They have same electronic configuration
(3) They form double bonds
(4) None of these

Question. Element X forms a chloride with formula XCl₄ which is a solid with low melting point. X would most likely be in the same group of the periodic table is 
(1) Na
(2) Mg
(3) Al
(4) Si

Question. If an element belongs to group 13 and the second period of the periodic table, which of the following sets of properties would it exhibit ? 
(1) Liquid, most metallic
(2) Gaseous, moderately metallic
(3) Solid, non-metallic
(4) Solid, less metallic

Question. Which of the following increases along the period ?   
(1) Number of valence electrons
(2) Atomic size
(3) Electropositive character
(4) All of these

Question. Which of the following elements has three valence electrons ?   
(1) Cs
(2) Ca
(3) Al
(4) S

Question. Each of the following element forms univalent ions except   
(1) Li
(2) Na
(3) Mg
(4) K

Question. The ‘law of octaves’ was enunciated by   
(1) Lother Meyer
(2) Mendeleev
(3) Dobereiner
(4) Newlands

Question. The noble gases are unreactive because     
(1) they react with sodium
(2) they have a full outer shell of electrons
(3) they have a half-filled outer shell of electrons
(4) they have large number of neutrons

Question. Which set of the elements have four electrons in their valence shell ?   
(1) C, Si, Sn
(2) O, S, Se
(3) B, Al, Ga
(4) Ne, Ar, Kr

Question. An element M has an atomic number 9 and atomic mass 17. Its ion will be represented by   
(1) M
(2) M+2
(3) M–
(4) M–2

Question. Which of the following pairs are chemically dissimilar ?   
(1) Na, K
(2) Ba, Sr
(3) C, Si
(4) Ca, Cs

Question. The valency of noble gases, in general is 
(1) zero
(2) one
(3) two
(4) eight

Question. In the third period of the periodic table, the element having smallest size is 
(1) Na
(2) Ar
(3) Cl
(4) Si

Question. Among O, C, F, Cl, Br the correct order of increasing atomic radii is
(1) F,    O,   C,   Cl,   Br
(2) F,    C,   O,   Cl,   Br
(3) F,    Cl,  Br,   O,   C
(4) C,   O,   F,    Cl,   Br

Question. Alkali metals in each period have 
(1) Smallest size
(2) Lowest I.E.
(3) Highest E.A.
(4) Highest electronegativity

Question. From top to bottom in a group of the periodic table the electropositive character of the elements 
(1) increases
(2) decreases
(3) remains unchanged
(4) changes irregularly

Question. Elements of which group form anions most readily 
(1) oxygen family
(2) nitrogen group
(3) halogens
(4) alkali metals

Question. Arrange S, O and Se in ascending order of electron affinity ?   
(1) Se < S < O
(2) Se < O < S
(3) S < O < Se
(4) S < Se < O

Question. Which element has the largest size in the second period ? 
(1) N
(2) F
(3) Li
(4) Be

Question. Which has the maximum atomic radius ? 
(1) Al
(2) Si
(3) P
(4) Mg

Question. Considering the elements B, Al, Mg and K, the correct order of their metallic character is 
(1) B > Al > Mg > K
(2) Al > Mg > B > K
(3) Mg > Al > K > B
(4) K > Mg > Al > B

Question. Which of the following elements will form an acidic oxide?   
(a) An element with atomic number 7
(b) An element with atomic number 3
(c) An element with atomic number 12
(d) An element with atomic number 19

Question. The positions of four elements A, B, C and D in the modern periodic table are shown below Which element is most likely to form an acidic oxide? 
(a) A
(b) B
(c) C
(d) D

Question. In Mendeleev’s periodic table, gaps were left for the elements to be discovered later. Which of the following element found a place in the periodic table later?   
(a) Germanium
(b) Chlorine
(c) Oxygen
(d) Silicon

Question. Which one of the following does not increase while moving down the group of the periodic table?         
(a) Atomic radius
(b) Metallic character
(c) Valence
(d) Number of shells in an element

Question. On moving from left to right in a period in the periodic table, the size of the atom:       
(a) increases
(b) decreases
(c) does not change appreciably
(d) first decreases and then increases

Question. An element X with atomic number 12 forms a compound with element Y with atomic number 17. The formula of the compound formed is:           
(a) XY
(b) XY2
(c) X2Y
(d) X2Y3

Question. Which of the following statements about the modern periodic table is correct?     
(a) It has 18 horizontal rows known as periods.
(b) It has 7 vertical columns rows known as periods.
(c) It has 18 vertical columns known as groups.
(d) It has 7 horizontal rows known as groups.

Fill in the blanks

(a) The elements are arranged in such a way that ………….. are on left side of zig-zag line and ………….. on the right side.

(b) In the Mendeleev’s periodic table, properties of elements are periodic function of their …………….

(c) In the modern periodic table,, the elements are the periodic function of …………….

Assertion and Reasoning Based Questions

Directions : In the following questions, a statement of assertion is followed by a statement of reason. Mark the correct choice as :
(a) If both assertion and reason are true and reason is the correct explanation of assertion.
(b) If both assertion and reason are true, but reason is not the correct explanation of assertion.
(c) If assertion is true, but reason is false.
(d) If assertion is false but reason is true.

Question. Assertion : Chlorine is less electronegative than fluorine.
Reason : It is because of its small size.
Answer : (b) Electronegativity decreases in a group from top to bottom. Thus, chlorine is less electronegative than fluorine. Thus both assertion and reason are true, but reason is not the correct explanation of the assertion.

Question. Assertion : Mendeleev’s periodic table was not widely accepted.
Reason : It is because hydrogen was not placed properly.
Answer : (b) Mendeleev’s periodic table was not widely
accepted because all the properties were not explained and also the anomalous behaviour of hydrogen was not explained. Thus both assertion
and reason are true, but reason is not the correct explanation of the assertion.

Question. Assertion : Periodicity in elements is the basis for the periodic table.
Reason : Henry Mosley gave the modern periodic law.
Answer : (b) Repetition of properties after regular intervals is the main cause of periodicity of elements. Thus both assertion and reason are true, but reason is not the correct explanation of the assertion.

Question. Assertion : Across a period atomic radius decreases.
Reason : It is because electron is added to the same shell.
Answer : (a) Atomic radius decreases across a period because electron is added in the same shell. So attraction between nucleus and valence shell increases due to which outermost shell is pulled closer to the nucleus. Nuclear charge is also increasing. Thus, effective nuclear charge increases and atomic size decreases. Thus both assertion and reason are true and reason is the correct explanation of the assertion.

Question. Assertion : Sodium is a metal whereas sulphur is a nonmetal.
Reason : From left to right metallic character decreases.
Answer : (a) Metallic character of elements decreases in a period from left to right. Hence, sodium which is at left is metal and sulphur is a non-metal. Thus both assertion and reason are true and reason is the correct explanation of the assertion.

Creating Based Questions

Question. Oxygen (atomic number 8) and sulphur (atomic number 16) belong to group 16 of the periodic table. Write the electronic configuration of the two elements. Which of them will be more electronegative ? Why ?
Answer : Oxygen has atomic number 8, electronic configuration will be → 2, 6.
Sulphur has atomic number 16, electronic configuration will be → 2, 8, 6. 
Oxygen with two shells will be more electronegative because it can easily gain electron due to its smaller size of atom, the nuclear charge attracts the electron easily to become negative ion.

Question. (a) The electronic configuration of an atom is 2, 8, 7.
Give its atomic number, nature of oxide.
(b) An element has an atomic number of 15 with which of the following elements will it show similar chemical properties :
(a) Be (4), (b) Ne (10), (c) N (7), (d) O (8).
(c) What will be the group number and period number respectively of an element X with atomic number 8 ?
Answer : (a) Atomic number is 17. As it is a non-metal, it will form acidic oxide.
(b) The electronic configuration of element with atomic number 15 will be : 2, 8, 5 and from the given options, N (7) has the similar electronic configuration : 2, 5. So, N will show similar chemical properties. 
(c) The electronic configuration of the element X would be 2, 6. Now, as there are 6 electrons in outer shell, it will be placed in 6th group and as there are only two shells filled with electrons, it will be placed in 2nd period.

Question. Write the atomic numbers and names of following elements :
(a) An element whose atom has 3 shells with 4 electrons in outermost shell.
(b) An element whose atom has twice as many electrons in its second shell as in its first shell ?
Answer : (a) The electronic configuration can be written as 2, 8,
4 here. So, the atomic number would be 14 and the element is silicon (Si).
(b) First shell has 2 electrons; hence second shell would have 4 electrons. So, the electronic configuration becomes 2, 4 and hence the atomic number is 6 and the element is carbon.

Question. An element X forms a chloride with the formula XCl2, which is a solid with a high melting point. Predict the most likely outer orbital electronic configuration of X and also name two more elements from same group of the Periodic Table to which elements X belongs.
Answer : The element X has 2 electrons in outer orbital as it forms a dichloride (XCl2). So, this element belongs to group 2 of periodic table. Other elements of group 2 are magnesium (Mg) and beryllium (Be).

Question. Write the contrasting points present in modern periodic table, against the following given points of Mendeleev’s table :
(a) Elements arranged according to atomic mass.
(b) It has 8 groups and 6 periods.
Answer : The contrast points can be written as :
(a) In modern periodic table the elements are arranged according to atomic number.
(b) Modern periodic table has 18 groups and 7 periods.

Paragraph/Table and Case Study Based Questions

1. Read the following and answer any four questions from 1(i) to 1(v).
The following table shows the position of six elements A, B, C, D, E, F, G, H, I, J, K, L, M, N in the period table.

With reference to the table, answer the following:

(i) Which elements have complete outer electronic configuration?
(a) F and J
(b) D and E
(c) E and N
(d) M and N

(ii) Atomic size refers to the radius of an atom. The atomic size may be visualised as the distance between the centre of the nucleus and the outermost shell of an isolated atom. Study the given graph which represents the trend of atomic size with respect to the periodic table

Which of the following is the correct order for atomic size?
(a) A > B > C > D > E
(b) F < G < H < I
(c) J > K > L < M > N
(d) E < F < G < H < I

(iii) Which of the following states Modern Periodic Law?
(a) Properties of elements are a periodic function of their atomic number
(b) Properties of elements are a periodic function of their atomic size
(c) Properties of elements are a group function of their atomic number
(d) Properties of elements are a periodic function of their valency

(iv) Which of the following reason correctly justifies that “bromine has smaller atomic radius than potassium”?
(a) Br and K are in the same group. Atomic size increases down the group
(b) Br and K are in the same period. Atomic size increases across the period due to increase in number of shells
(c) Br and K are in the same group. Atomic size decreases down the group
(d) Br and K are in the same period. Atomic size decreases across the period from left to right.

(v) Identify the correct elements from the table.
(a) B- boron, C- Neon, M- oxygen
(b) G-aluminium, I- Chlorine, K-calcium
(c) F- sodium, K- caesium, L- Lithium
(d) B- boron, H- carbon, L- Nitrogen

Read the following and answer any four questions from 3(i) to 3(ii):
The term atomic size refers to the radius of an atom.
The atomic size may be visualised as the distance between the centre of the nucleus and the outermost shell of an isolated atom. The atomic radius of hydrogen atom is 37 pm (picometre, 1 pm = 10^–12m).

(i) What is atomic radius?
(a) Distance between two adjacent electrons of an atom of an element.
(b) Shortest distance between the nucleus and the outermost shell of an atom.
(c) The circumference of the outermost shell of the atom.
(d) The circumference of the nucleus of the atom.

(ii) If the atomic radius of Helium is 1.4 × 10^–10 m, then what is its atomic size?
(a) 1.4 pm
(b) 14 pm
(c) 140 pm
(d) 1400 pm

(iii) Calcium has bigger atomic radius than Cobalt. Why?
(a) Being in the same period, both have same number of shells, but the cobalt has bigger atomic number which reduces its atomic radius.
(b) Being in the same group, both have same number of shells, but the cobalt has bigger atomic number which reduces its atomic radius.
(c) Being in the same group, both have same number of valence electrons
(d) Calcium has bigger atomic number than cobalt which increases its atomic radius.

(iv) Which property of atomic size of elements can be depicted by the graph?

(a) Atomic size decreases down the group.
(b) Atomic size decreases from left to right in the period.
(c) Atomic size increases down the group.
(d) Atomic size increases from left to right in the period.

(v) Observing the graph, arrange the elements in the decreasing order of their atomic size.

(a) Mg > Si > Cl > Ar
(b) Ar > Si > Cl > Mg
(c) Ar > Cl > Si > Mg
(d) Ar > Cl > Mg > Si

4. Read the following and answer any four questions from 3(i) to 3(v):
Periodic properties (physical or chemical) show a variation with change in atomic number. In modern periodic table elements are arranged according to their atomic numbers, configuration of electrons and chemical properties.

(i) Among the following which is not a periodic property?
(a) Ionisation energy
(b) Atomic size
(c) Specific heat
(d) Electronegativity

(ii) Atomic size decreases on moving from left to right in a period in the periodic table. Decrease in atomic size along a period is attributed due to the ……………
(a) increased nuclear charge
(b) addition of new shells
(c) increased charge density
(d) none of these

(iii) Three elements B, Si and Ge are …………..
(a) metals
(b) non-metals
(c) metalloids
(d) metal, non-metals and metalloids respectively

(iv) Choose the correct combination provided in the following table:

(v) Study the table below & choose the correct option:
Column-I                                                        Column-II
(A) Element having atomic number 19.       (p) Europium
(B) Traids rule is given by                              (q) II-A group
(C) Rare earth element                                   (r) Dobereiner
(D) Transition element                                   (s) Cr
(a) A–q, B–r, C–p, D–s
(b) A–r, B–p, C–s, D–q
(c) A–p, B–q, C–s, D–r
(d) A–q, B–p, C–r, D–s