if atomic number is 107 find in which group(group no ) and period it belong to, in modern periodic table ?? plz explain the process

From atomic number of an element, we can write its electronic configuration. 

Depending upon the number of electrons present in valence shell, we can come to know about group number of the element. For example, Atomic number of 107. So its electronic configuration will be: [Rn] 5f¹⁴6d⁵7s²
  Number of valence electron is 7 so its group number is 7.

Principal energy level, in which valence electrons are filled indicates the period number of the element. For example, atomic number of element is 107 so its electronic configuration will be: 

[Rn] 5f¹⁴6d⁵7s² 

Here valence electrons are present in shell having value n=7

So its period number is 7

Hope it helps!