Chapter U1.10, Problem 1TAI

Interpretation Introduction

Interpretation:

The information about the elements revealed by the periodic table needs to be explained.

Concept introduction:

All the known elements are placed in the long form of the periodic table. Because of the presence of large number of elements, it is necessary to arrange the elements 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

Different properties of elements which revealed by the periodic table are as follows:

• Atomic radii variation
• Ionization energy
• Electron affinity
• Metallic nature of element
• Chemical reactivity of elements

Explanation of Solution

In the long form of periodic table; alkali metals, alkaline earth metals, halogen and Noble gases are name of certain groups. In periodic table, the vertical columns are called as groups whereas the horizontal rows are called as period.

On moving down the group, the atomic size of elements increases. As the atomic size increases the reactivity of metallic element increases. This is because as the atomic size increases, the nuclear attraction decreases for valence electrons and it becomes easier to excite it during different chemical reactions. Therefore the chemical reactivity increases down in the group.

As the atomic size increases down in the group, the ionization energy decreases as less energy is needed to remove electron from the valence shell. The metallic nature also increases with decreasing the ionization energy as elements become more reactive on moving down the group.

Conclusion

Thus, different properties of elements revealed by the periodic table are as follows:

• Atomic radii variation
• Ionization energy
• Electron affinity
• Metallic nature of element
• Chemical reactivity of elements