Chapter U1.24, Problem 1TAI

Interpretation Introduction

Interpretation:

The arrangement of electrons needs to be explained with the help of periodic table.

Concept introduction:

A periodic table was developed by scientists to arrange the elements based on the patterns in their properties. Modern periodic table is a storehouse of information about the elements. There are 18 vertical columns called groups and 7 horizontal rows called periods in a periodic table. Each element square contains information such as element name, symbol, atomic number and average atomic mass.

Answer to Problem 1TAI

From the location of the element in the periodic table one can know the number of shells and subshells present in the atom of the element. The number of the period gives us information about the number of shells present in the atom.

A periodic table can be divided into four zones, s block, p block, d block and f block. The element belonging to a particular block will have its outermost electron in that particular subshell. On moving across the periodic table of subshells, one can write the electron configuration of that element by writing the subshells.

Explanation of Solution

Electrons revolve around the nucleus in orbits. These orbits are called shells. The shells are numbered as n = 1, 2, 3, 4… and so on. Number of shells in an atom is the same as the number of period where the atom is located on the periodic table. The shells are divided into subshells. Number of subshells in each shell is equal to n. The subshells are referred to as s, p, d, and f subshells. These subshells can have a maximum of 2, 6, 10 and 14 electrons respectively. The electrons can be arranged in a shorthand notation form called electron configuration. A periodic table can be divided into four zones, s block, p block, d block and f block. Elements belong to one of these four zones.

The element belonging to a particular block will have its outermost electron in that particular subshell.

To write the electron configuration of a particular element, one can simply trace the location of the element in periodic table and determine the subshells in which the outermost electron is present.

Conclusion

By knowing the position of an element on a periodic table, one can predict the arrangement of electrons. The periodic table provides the information needed to write electronic configurations.