Why are there 8 elements in the second period?
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Answered by
9
Hey !!
The modern periodic table is arranged in order of increasing atomic number and the elements of the similar properties are placed in the same group. In this way modern periodic table is arranged and from this arrangement we get 2 elements in first period, 8 elements in second and third period , 18 elements in 4th, 5th period and so on.
OR
If you know about electronic configuration then according to it
the elements are divided into shell
so the 1 shell=max 2 electron
2 shell= max 8 electron
3 shell= max 8 electron
4 shell= max 8 electron
5 shell = max 18 elements and so on
therefore the first group of elements have 1 shell so it is called as 1 period and has one element as position of hydrogen is not fixed.
second, third contains 8 electron and remaining other contains 18 electrons as according to their valence shells but the middle elements also called transition elements are not included while calculating the basic electronic configuration. This table was made to arrange the elements according to their properties
The modern periodic table is arranged in order of increasing atomic number and the elements of the similar properties are placed in the same group. In this way modern periodic table is arranged and from this arrangement we get 2 elements in first period, 8 elements in second and third period , 18 elements in 4th, 5th period and so on.
OR
If you know about electronic configuration then according to it
the elements are divided into shell
so the 1 shell=max 2 electron
2 shell= max 8 electron
3 shell= max 8 electron
4 shell= max 8 electron
5 shell = max 18 elements and so on
therefore the first group of elements have 1 shell so it is called as 1 period and has one element as position of hydrogen is not fixed.
second, third contains 8 electron and remaining other contains 18 electrons as according to their valence shells but the middle elements also called transition elements are not included while calculating the basic electronic configuration. This table was made to arrange the elements according to their properties
Answered by
13
The elements are ordered into periods based on which electron shells are being filled (from left to right). ... In the second period, the second shell is being filled. And so on. There are 8 elements in period 2 because all those elements have electrons in the second shell and no electrons in the third shell.
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