How to Classify Elements

Periodic trends of Elements in groups and periods.

Created byVinay Arya

Last updated 10/2021

English

What you'll learn

The students will have a clear vision about the Periodic Table.
They will know about different Groups and periods.
They will understand the concept of Blocks.
They will be perfect in Periodic Trends.

Course content

1 section • 12 lectures • 1h 55m total length

Introduction8:50
Explore the periodic table, unveiling how elements are classified by atomic numbers, moved left to right into blocks and groups, with references to lanthanides and actinides.
Contents of How to Classify Elements7:10
Describe how the periodic table classifies elements, from Newlands' octaves and the Devonian approach to modern periodic law and the long-form periodic table, emphasizing atomic number and periodic trends.
Need of Classification of Elements8:09
Understand the need for classification as the number of elements grew, and see how scientists grouped similar elements into vertical columns to form the periodic table and predict their properties.
Earlier attempts of Classification1:17
Examines early attempts to classify elements, from grouping by similar properties to using atomic masses to predict relationships, and introduces Newlands octaves.
Mendeleev's Periodic Table14:43
Learn how Dmitri Mendeleev proposed the periodic table and the periodic law, arranging elements by increasing atomic weights to reveal repeating properties and gaps for undiscovered elements.
Merits of Mendeleev's Periodic Table7:03
Analyze the merits of Mendeleev's periodic table: systematic element classification, gaps for undiscovered elements, and predicted properties; and correct atomic weights for elements like beryllium, gold, and platinum.
Defects of Mendeleev's Periodic Table7:44
Defects of Mendeleev's periodic table are explored, including hydrogen placement, isotopes, atomic-mass inversions, and misgrouping of similar and dissimilar elements, motivating a revised periodic table.
Modern Periodic law and long form of periodic table15:20
Discover how the modern periodic law uses atomic number to explain the periodic recurrence of element properties, yielding the long-form periodic table with 18 groups and s, p, d blocks.
Periodic trends in Groups16:42
Explore how periodic trends in groups shape atomic properties, including atomic number, valence electrons, ionization energy, electron affinity, electronegativity, and metallic versus nonmetallic character.
Periodic trends in Periods14:23
Explore how periodic trends arise across a period, including ionization energy, atomic size, electron affinity, electronegativity, and metallic versus nonmetallic character.
Grouping of elements into blocks8:19
Classify elements into s, p, d, and f blocks based on configuration, with alkali metals in the s-block, transition metals in the d-block, and lanthanides and actinides in the f-block.
Merits and Defects of Long Form of Periodic Table5:57
Explore the merits and demerits of the long form periodic table, including its basis on atomic number and electron configuration, anomaly removal, and ongoing spiral table developments.

Requirements

The students should have a idea about elements.

Description

Before the nineteenth century, only a few elements were known. These elements could

be easily studied individually.

With the passage of time, many more elements were discovered. More and more of

their compounds were prepared. Study of these elements and compounds individually

became more difficult. So, it was felt that these elements should be classified into a

few groups to make their study systematic and easier. It is expected that a systematic

classification will help us in

• organising the knowledge,

• predicting new elements for undertaking further studies.

One of the earliest attempts towards the classification of elements was to divide these

into metals, and non-metals.

This method of classification failed because most of the elements fell into the

category of metals, whereas only a few elements could be grouped as non-metals.

There were also a few elements which showed the properties of both metals and

non-metals.

Since then, many attempts were made by various scientists to classify elements

in a more systematic way. A few important attempts for the classification of

elements are described over here. There are more than one hundred chemical elements

known today. It is very difficult to study the properties of each element individually, so

these elements were classified on the basis of their similarities in properties. In this

course, we shall discuss the historical development of Mendeleev's periodic table,

modern periodic law and the electronic configuration of atoms as the basis for periodic

classification, the characteristics of s, p, d, f block elements and the periodicity

in physical and chemical properties of the elements.

Who this course is for:

Biggane and eleventh standard students.