Name: Nomenclature of Elements With Atomic Numbers > 100
Uploaded: 2019-07-19
Duration: 16 min 52 s
Description: Elements with atomic number greater than 100 have been named after famous scientists, although the universally accepted names are the names derived from IUPA...

Question

Describe the long form of periodic table. What advantages it has over the Mendeleev's periodic table?

Accepted Answer

In the long form of periodic table the elements are arranged in the order of increasing atomic number. This table has seven horizontal rows called periods and eighteen vertical columns known as groups.
Period : The seven periods are represented as period $1$ to $7$ . First period contains two elements hydrogen and helium. The second period has $8$ elements. There are eight elements in the third period also. The fourth period starts with potassium and ends with krypton has ten more elements than the earlier one (eighteen elements in all). The fifth period is similar to the fourth one. However, the sixth period ( $n = 6$ ) has $32$ elements. The seventh period would have been similar to the sixth period, but it is incomplete.

Group : There are eighteen groups in a periodic table. Group 1 consists of elements hydrogen, lithium, sodium, potassium etc. All these elements have the common outermost electronic configuration ${ns}^{1}$ . The elements of Group 2, have ${ns}^{2}$ configuration. Similarly elements from Group $13$ to group 18 have common electronic configuration varying from ${ns}^{2} {np}^{1}$ to ${ns}^{2} {np}^{6}$ . In addition to the above group ten more columns are present between group $2$ and $13$ . The elements present in them have common electronic configuration $(n - 1) d^{1 - 10} {ns}^{0 - 2}$ .

Advantages of long form of periodic table over the Mendeleev's periodic table:

1. Mendeleev's periodic table was based on atomic mass while long form of periodic table is based on atomic number.

2. Long form of periodic table explains periodicity of properties of elements based on electronic configuration.

3. Lanthanides and actinides are placed separately.

QUESTIONS

Odisha Board Chemistry Solutions for Exercise - QUESTIONS

Questions from QUESTIONS with Hints & Solutions

Learn and Prepare for any exam you want !