Question

the diagram below show part of the periodic table the position of element in the periodic table is shown first to write the atomic number of the element second give the electronic distribution of the element third using these three element as example described the trend in the chemical property across the third period of the periodic table​

Answer 1

Explanation:

The electronic configuration of elements and their position in the periodic table are related to each other. From the electronic configuration of elements, we can determine the period and group to which the elements belongs.

Consider sodium with atomic number 11. K,L and M shells have 2,8 and 1 electron each. Since there are 3 principal energy levels, sodium belongs to third period.

M shell (valence shell) has only 1 electron. So sodium belongs to group 1 or IA.

Now consider chlorine with atomic number 17. K,L and M shells have 2,8 and 7 electron each. Since there are 3 principal energy levels, chlorine belongs to third period.

M shell (valence shell) has7 electrons. So chlorine belongs to group 7 or VIIA.