Chapter U1.9, Problem 1TAI

Interpretation Introduction

Interpretation:

The periodic table needs to be explained.

Concept introduction:

All known elements are placed in the long form of periodic table. Because of the presence of large number of elements, it is necessary to arrange the element in certain arrangement for their proper study.

The long form of the periodic table is a tabular arrangement of all known elements. In this table, all elements are placed in order of increasing atomic number. Here atomic number indicates the number of protons in an atom of the element.

Answer to Problem 1TAI

In the periodic table, there are:

• 18 groups and 7 periods
• two series of 14 elements at the bottom of the main body
• Four block on the basis of valence shell electronic configuration of elements;
• s-block elements
• p-block elements
• d-block elements
• f-block elements

Explanation of Solution

In periodic table, the groups are the vertical columns whereas the horizontal rows are period.

There are 18 groups and 7 periods in the long form of periodic table. All the elements are arranged in increasing order of their atomic number in these groups and periods.

There are two series of 14 elements at the bottom of the main body of the periodic table which are placed separately because they show different chemical and physical properties compared to other elements.

All the elements in the same group show trends in their properties such as atomic size increases down in the group whereas it decreases across the period.

The periodic table can be classified in four blocks on the basis of valence shell electronic configuration of elements;

• s-block elements
• p-block elements
• d-block elements
• f-block elements

Conclusion

Thus, in the periodic table there are:

• 18 groups and 7 periods
• two series of 14 elements at the bottom of the main body
• Four block on the basis of valence shell electronic configuration of elements;
• s-block elements
• p-block elements
• d-block elements
• f-block elements