How can we find period no. from the modern periodic table?

1.	How can we find period no. from the modern periodic table?
Answer» The period of an element corresponds to the principal quantum number of the valence shell. The block of an element corresponds to the type of orbital which receive the last electron.Example: Predict the period number atomic number 29.The period of the element = No. of principal quantum number of the valence shell = 4th

Discussion