NCERT Solutions for Class 10 Science Chapter 5 Periodic Classification of Elements
NCERT solutions for class 10 science chapter 5 - Periodic Classification of Elements is the 5th chapter of NCERT Class 10 science book. While studying this chapter and solving questions, students can get help from NCERT Periodic Classification of Elements Class 10 Science chapter 5 solutions for more clarification. In NCERT solutions for Class 10 Science chapter 5, we have provided solutions for all the questions asked in the book. Students looking for NCERT Solutions for Periodic Classification of Elements Class 10 science chapter 5 pdf download can be used to prepare offline.
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This article is helpful to understand the solutions related to the elements in the Modern Periodic Table. They are arranged in 18 vertical columns called groups and 7 horizontal rows called periods.
Also Read,
- Periodic Classification of Elements Class 10 NCERT Exemplar Solutions
- Periodic Classification of Elements Class 10 NCERT Chapter Notes
After going through the NCERT solutions for class 10 science, you will be able to get the solutions for the questions which are mentioned below:
NCERT Solutions for Class 10 Science Chapter 5 Periodic Classification of Elements
Topic 5.1 Making order out of chaos - Early attempts at the classification of elements
Q.1. Did Döbereiner’s triads also exist in the columns of Newlands’ Octaves? Compare and find out.
Answer:
Yes, Dobereiner's triads also exist in the column of Newland's octaves.
Newland's law of octaves, says that every eight elements had properties similar to that of the first.
For example, the element Lithium, sodium, and potassium are present in the second column of Newland's classification of elements. If lithium is the first element then, the sodium will be the 8th element and considering again sodium as the 1st element, then the 8th element will be potassium.
So, that means according to Newland's Law of octaves, lithium, sodium, and potassium should have similar properties and also these elements form a Dobereiner's traid having similar chemical properties.
Q.2. What were the limitations of Döbereiner’s classification?
Answer:
The limitation of Doberenier's classification:
Döbereiner could identify only three triads from the elements known at that time. Hence, this system of classification into triads was not found to be useful.
Q.3. What were the limitations of Newlands’ Law of Octaves?
Answer :
The limitations of Newland's law of octaves are:
(1) It was found that the Law of Octaves was applicable only up to calcium, as after calcium every eighth element did not possess properties similar to that of the first.
(2) It was assumed by Newlands that only 56 elements existed in nature and no more elements would be discovered in the future. But, later on, several new elements were discovered, whose properties did not fit into the Law of Octaves.
(3) Newland put two elements together in one slot and that too in the column of unlike elements having different properties.
Example: Cobalt and Nickel were put together in just one slot and that too in the column of elements like fluorine, chlorine, and bromine which were very different properties from these elements.
CBSE NCERT solutions for class 10 science chapter 5 Periodic Classification of Elements
Topic 5.2 Making order out of chaos: Mendeléev’s Periodic Table
Q.1. (a) Use Mendeléev’s Periodic Table to predict the formulae for the oxides of the element:
- K
Answer:
The general formula for the oxides of the element Potassium (K): Potassium belongs to the group I of Mendeleev's periodic table, Hence, the formula of its oxide will be
Q.1. (b) Use Mendeléev’s Periodic Table to predict the formulae for th e oxides of the element:
- C
Answer:
The general formula for the oxides of the element Carbon (C): Carbon belongs to the group IV of Mendeleev's periodic table,
Hence, the formula of its oxide will be
Q.1. (c) Use Mendeléev’s Periodic Table to predict the formulae for the oxides of the element :
- Al
Answer:
The general formula for the oxides of the element Aluminium (Al): Aluminum belongs to the group III of Mendeleev's periodic table,
Hence, the formula of its oxide will be
Q.1. (d) Use Mendeléev’s Periodic Table to predict the formulae for the oxides of the following elements:
- Si
Answer:
The general formula for the oxides of the element Silicon (Si): Silicon belongs to the group IV of Mendeleev's periodic table,
Hence, the formula of its oxide will be
Q.1. (e) Use Mendeléev’s Periodic Table to predict the formulae for the oxides of the element:
- Ba
Answer:
The general formula for the oxides of the element Barium (Ba): Barium belongs to the group II of Mendeleev's periodic table,
Hence, the formula of its oxide will be
Answer:
Besides gallium Scandium (Sc) and Germanium (Ge) elements have been discovered for which gaps were left by Mendeleev in his periodic table.
Q.3. What were the criteria used by Mendeléev in creating his Periodic Table?
Answer:
The criteria used by Mendeleev in creating his periodic table were:
(i) The atomic mass of the elements was used to arrange the elements.
(ii) Grouping the elements according to their similar chemical properties.
And hence proposed that the chemical properties of the elements are the periodic function of their atomic masses and thus he arranged the elements according to the increasing order of atomic masses.
Q.4. Why do you think the noble gases are placed in a separate group?
Answer:
Noble gases are inert nature elements. In the periodic table, they are placed in a separate group because they have a unique property and are very different from other elements.
NCERT solutions for class 10 science chapter 5 Periodic Classification of Elements
Topic 5.3: Making order out of chaos: The Modern Periodic Table
Q.1. How could the Modern Periodic Table remove various anomalies of Mendeléev’s Periodic Table?
Answer:
Modern periodic table removes, various anomalies of Mendeleev's periodic table as follows:
(1) In the modern periodic table, elements are arranged in the increasing order of their atomic number, not in the atomic mass.
(2) In the modern periodic table, the isotopes are placed in the same place as they having the same atomic number but different atomic masses.
(3) Now, the same group elements have the same number of valence electrons.
(4) Hydrogen is now placed in the group containing the same valence electrons.
Answer:
Elements that show similar chemical reactions are Beryllium (Be) and Calcium (Ca) because they belong to the same group. i.e., group 2nd in the modern periodic table
Q.3. (a) Name
- Three elements that have a single electron in their outermost shells.
Answer:
Single valence electron elements are: (a) Lithium, Sodium, and Potassium .
Q.3.(b) Name
Answer:
Magnesium and Calcium have two electrons in their outermost shells.
Q.3. (c) Name
Answer:
The elements which have fully filled outermost shells are noble gases.
Example: Helium, Neon, and Argon.
Answer:
Yes , they have the following similar properties:
(1) Belongs to the same group I in the periodic table.
(2) Have 1 valence electron in the valence shell.
(3) All are alkali metals.
(4) They are highly reactive.
Answer:
Both Helium and Neon are noble gases which belong to the zero groups in the modern periodic table. They have fully filled the outermost shell with electrons. Helium has two electrons in its K shell whereas Neon has 8 electrons in its outermost shell.
Q.5. In the Modern Periodic Table, which are the metals among the first ten elements?
Answer:
Among the first ten elements metals are only 2 elements:
Lithium (Li) and Beryllium (Be) .
Answer:
The metallic character of the elements decreases as we move horizontally from left to right in the periodic table.
Therefore, Be will have the maximum metallic character because of its extreme left position in the periodic table.
NCERT solutions for class 10 science chapter 5 Periodic classification of elements- Exercise solutions
Q.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.
(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:
When going from left to right across the periods of the periodic table, the number of valence electrons increases. So, the tendency to lose electrons decreases whereas to accept electron increases.
Hence the option (C) is incorrect.
Answer :
X must be Magnesium (Mg) which has a valency of 2 and when it combines with chlorine having valency 1, it forms .
Hence, the option (B) is correct.
Q.3.(a) Which element has
- two shells, both of which are completely filled with electrons?
Answer:
The element which has two shells, which are both completely filled with electrons is,
Neon with electronic configuration .
Q.3.(b) Which element has
- The electronic configuration 2, 8, 2?
Answer:
The given electronic configuration is of Magnesium (Mg).
Q.3. (c) Which element has
- A total of three shells, with four electrons in its valence shell?
Answer:
The element having three shells and four electrons in its valence shell is Silicon (Si) .
Q.3. (d) Which element has
- A total of two shells, with three electrons in its valence shell?
Answer:
The element having two shells and three electrons in its valence shell is Boron (B) .
Q.3. (e) Which element has
- Twice as many electrons in its second shell as in its first shell?
Answer:
The element having twice as many electrons in its second shell as in its first shell will be:
Carbon with electronic configuration:
Q.4. (a) What property do all elements in the same column of the Periodic Table as boron have in common?
Answer:
The same column of the periodic table as boron belongs to the group 13th has 3 valence electrons,
Hence, its valency is 3.
Therefore, all the elements in the same column of the periodic table as Boron will have a valency of 3.
Q.4. (b) What property do all elements in the same column of the Periodic Table as fluorine have in common?
Answer:
Fluorine belongs to the group 17th in the periodic table and having 1 valence electron.
Hence its valency is 1.
Therefore, all elements in the same column of the periodic table as fluorine will have a valency of 1.
Q.5. An atom has electronic configurations 2, 8, and 7.
(a) What is the atomic number of this element?
(b) To which of the following elements would it be chemically similar? (Atomic numbers are given in parentheses.)
- N(7) F(9) P(15) Ar(18)
Answer:
The electronic configuration: is of Chlorine.
(a) The atomic number of this element will be: .
(b) It will be chemically similar to the element Fluorine (9) as it also has the same number of valence electrons in its valence shell.
Q.6. (a) The position of three elements A, B and C in the Periodic Table are shown below–
Group 16 | Group 17 |
- | - |
- | A |
- | - |
B | C |
- State whether A is a metal or non-metal.
Answer:
As we know in the periodic table, group 3 - group 12 are transition metals and group 13 to group 16 are metalloids and then there are halogens in 17 groups.
A is in group 17 so it is a non-metal.
Q.6.(b) The position of three elements A, B, and C in the Periodic Table are shown below –
Group 16 | Group 17 |
- | - |
- | A |
- | - |
B | C |
- State whether C is more reactive or less reactive than A.
Answer:
Element C is less reactive than A because in the halogens the reactivity decreases as we move down. This happens because as we move down the nuclear attraction increases due to an increase in atomic mass. Stronger attraction toward electron will make it harder to react with any other element that's why they are less reactive.
Q.6.(c) The position of three elements A, B and C in the Periodic Table are shown below –
Group 16 | Group 17 |
- | - |
- | A |
- | - |
B | C |
Will C be larger or smaller in size than B?
Answer:
C is much smaller than the size of the B because C has a higher atomic mass which means higher attraction to the electron which means compact (less) size.
Q.6. (d) The position of three elements A, B ,and C in the Periodic Table are shown below –
Group 16 | Group 17 |
- | - |
- | A |
- | - |
B | C |
- State whether A is a metal or non-metal.
- Which type of ion, cation or anion, will be formed by element A?
Answer:
A will form an anion as it accepts an electron to complete its octet.
Answer:
The electronic configuration of the element Nitrogen (N) is .
The electronic configuration of the element phosphorus (P) is
So, Nitrogen will be more electronegative than Phosphorus because its atom has a small size due to which the attraction of its nucleus for the incoming electron is more.
Answer:
The electronic configuration of an element gives the distribution of electrons in various shells present in the element. The atoms with similar electronic configuration are placed in the same column, hence groups have the same number of valence electrons.
Group number can be known by knowing the number of valence electrons.
The number of shells present in an element is equal to the period number.
Thus, the information of electronic configuration is enough to know the group and period number of an element.
Answer:
Element with atomic no. 12 and atomic no. 38 will have chemical properties the same as calcium. this is due to the fact that they have valency the same as calcium and also lie in the same group.
Answer:
Mendeleev's periodic table | Modern periodic table |
Elements are arranged in the increasing order of their atomic masses | Elements are arranged in the increasing order of their atomic numbers |
Consists of 8 groups | Consists of 18 groups |
Groups are categorized into subgroups 'a' and 'b' | No subdivision of groups. |
Noble gases were not grouped since they were not discovered yet | Noble gases were grouped together at the end of the table. |
There was no place for isotopes | Slots for isotopes present according to atomic number |
CBSE NCERT Solutions for Class 10 Science - Chapter wise
Chapter No. | Chapter Name |
Chapter 1 | Chemical Reactions and Equations |
Chapter 2 | Acids, Bases, and Salts |
Chapter 3 | Metals and Non-metals |
Chapter 4 | Carbon and its Compounds |
Chapter 5 | Periodic Classification of Elements |
Chapter 6 | Life Processes |
Chapter 7 | Control and Coordination |
Chapter 8 | How do Organisms Reproduce? |
Chapter 9 | Heredity and Evolution |
Chapter 10 | Light Reflection and Refraction |
Chapter 11 | The Human Eye and The Colorful World |
Chapter 12 | Electricity |
Chapter 13 | Magnetic Effects of Electric Current |
Chapter 14 | Sources of Energy |
Chapter 15 | Our Environment |
Chapter 16 | Sustainable Management of Natural Resources |
If you have any doubts about solving the questions or unable to answer them correctly then, don't worry NCERT Class 10 Science solutions chapter 5 are for you. For maths subject, you should visit NCERT class 10 Mathematics solutions.
Benefits of NCERT Solutions for Class 10 Science Chapter 5 Periodic Classification of Elements
These solutions cover all the questions mentioned in the chapter.
NCERT solutions for Class 10 science chapter 5 are prepared by the experts as per CBSE guidelines.
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Frequently Asked Question (FAQs) - NCERT Solutions for Class 10 Science Chapter 5 Periodic Classification of Elements
Question: What is the weightage of chapter 5 periodic classification of elements in CBSE class 10 board final exam?
Answer:
Questions of 5-6 marks can be asked from NCERT solutions for class 10 Science chapter 5.
Question: What are the important topics of Class 10 Science Chapter 5 periodic classification of elements ?
Answer:
Here is the list of important topics
Variation in Properties
Valency
Atomic number
Metallic and Non-metallic properties.
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Questions related to CBSE Class 10th
my sons dob is 13/02/2009 is hi eligible for 10th board exam in 2024,,from cbse. olz reply me
The eligibility age criteria for class 10th CBSE is 14 years of age. Since your son will be 15 years of age in 2024, he will be eligible to give the exam.
can Hindi marks be replace with IT 402(additional subject) in CBSE class 10th board
That totally depends on what you are aiming for. The replacement of marks of additional subjects and the main subject is not like you will get the marks of IT on your Hindi section. It runs like when you calculate your total percentage you have got, you can replace your lowest marks of the main subjects from the marks of the additional subject since CBSE schools goes for the best five marks for the calculation of final percentage of the students.
However, for the admission procedures in different schools after 10th, it depends on the schools to consider the percentage of main five subjects or the best five subjects to admit the student in their schools.
i got less marks in maths can it get replaced by additional hindi in cbse
Replacement of marks of additional subjects and your main course subject is not like they will swap the marks you got in Hindi and Mathematics on your marksheet. It works like if you calculate the total percentage you got in your class, you can take the marks of your additional subject to consider in place of the subject you have got the least marks in. CBSE schools consider this method only to release the merit list of their students.
If you're in 10th and aiming to get admission in 11th in any school, it depends on the schools if they consider your main five subject marks or the best five subject marks for the admission.
If you're in 12th and are trying for different colleges to get in, it depends on your course which you wish to study further and also some criterias and eligibility of the colleges. In most cases for general courses, colleges take the best three or best four subjects marks consideration for the admission process.
So, good luck.
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Central Board of Secondary Education will declare term 2 CBSE exam result 2022 for Class 10 in the third week of July. Please keep an eye on the official website or the link below for the latest information. Students need to enter their CBSE board roll number and other details to check term 2 cbseresults.nic.in 2022 Class 10 results. The board had announced the CBSE Class 10 results 2022 for term 1 on March 11, 2022.
cbse 10 claas bord result check now
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Class 10 cbse results are not out yet. It is expected to be declared on 23rd of July. Keep checking the official website of cbse.
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