State the number of elements
each periodic of a periodic table also
mention by what name they are called so.
Answers
Answer:-
Periods are the 7 horizontal rows in the periodic table.
First period :-
It contains only two elements Hydrogen and Helium. So, it is called as the Shortest period
Second period :-
It contains 8 elements – Li , Be , B , C , N , O , F , Ne. So, it is called Short period
Third Period :-
It also contains 8 elements – Na , Mg , Al , Si , P , S , Cl , Ar. It is also known as Short period.
Forth period :-
It contains 18 elements K to Kr. So , it is known as Long period
Fifth Period :-
It also contains 18 elements Rb to Xe. So, it is also called Long period.
Sixth period :-
It contains 32 elements Cs to Rn. So, it is the Longest period.
Seventh period :-
It contains 31 elements and it is an Incomplete period.
Answer:
Solution :-
✯︎ The modern periodic table was prepared by Niels Bohr. It is known as long form of the periodic table.
✯︎ This periodic table has 7 horizontal rows known as horizontal rows.
✪ The first period contains only 2 elements and is called very short period.
✪ The second and third period have 8 elements each and are known as short period.
✪ The fourth and fifth period have 18 elements each are known as long period.
✪ The sixth period has 32 elements and is called very long period.
✪ The seventh period contains rest of the elements and it is incomplete.
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✫Extra Information ✫
➣ The horizontal rows are called periods and the vertical columns are called groups.
➣ There are 12 horizontal rows or series and eight groups in the original periodic table proposed by Mendeleev.