NCERT Solutions for Class 10 Science, Chapter 5 - Periodic Classification of Elements

In this chapter, you’ll learn about the Periodic Classification of Elements. In earlier
classes, you have studied about elements, mixtures and compounds. In NCERT
Solutions for Class 10 Science, Chapter 5, you’ll study about different types of
elements known to us till date. Over a period of time, scientists have found 118
elements (94 are natural), observed their properties and classified them accordingly in
the form of the periodic table. It is an interesting timeline, from the time when the first
periodic table was designed, until today, where we have the modern periodic table.
Today, we have the privilege to refer to the periodic classification table as a cheat-sheet
and have a clear understanding of various elements.

Let’s take a look at topics and sub-topics of class 10 Science Chapter 5, Periodic Classification of Elements

5.1 Making Order out of Chaos – Early Attempts at the Classification of Elements
5.1.1 Döbereiner's Triads
5.1.2 Newlands' Law of Octaves
5.2 Making Order out of Chaos – Mendeléev's Periodic Table
5.2.1 Achievements of Mendeléev's periodic table
5.2.2 Limitations of Mendeléev's Classification
5.3 Making Order out of Chaos – The Modern Periodic Table
5.3.1 Position of Elements in the Modern Periodic Table
5.3.2 Trends in the Modern Periodic Table

In Class 10 Science Chapter 5, you will learn – 

Section 5.1 – In this section, you’ll study how scientists in earlier times tried to create
the periodic table of elements for a better understanding. This is the time when
elements were classified as metals and non-metals. In 1817, Johann Wolfgang
Döbereiner, a German chemist attempted the first periodic table, followed by an English
scientist, John Newlands in 1866 who arranged the elements based on their atomic
mass.

Section 5.2 – In this section, you’ll learn about Dmitri Ivanovich Mendeléev, a Russian
chemist, who is considered as the main contributor to the periodic table of elements,
where elements were categorised based on their basic property, atomic mass and
chemical properties. You’ll observe various pros and cons of the Mendeléev’s periodic
table.

Section 5.3 – In this section, you’ll study the modern periodic table. In 1913,
Henry Moseley showed that the atomic number (symbolised as Z) of an element is even
more important than its atomic mass. Thus, Mendeléev’s Periodic Law was changed and
the atomic number was considered as the basis of Modern Periodic Table.

In this chapter, you are provided with several activities and examples with their
solutions for a clear understanding of the Periodic Classification of Elements. To know more about NCERT Solutions for Class 10 Chemistry Chapter 5 you should explore the exercises mentioned in this chapter. You can also download the Periodic Classification of Elements Class 10 Solutions PDF, solved by our science experts.