What is the usual number of valence electrons in the atoms of the last element in a period?

What is the number of valence electrons in the atoms of first element in a period?

Find the number of unpaired electrons in the atom of the element having atomic number 16 .

What are valence electrons?

(i) The electronic configuration of an atom is [Z](n-2) f^(14)(n-1)d^(1)ns^(2) . What is the minimum position of the atom in the periodic table and correspondingly what is the atomic number of Z? (ii) Find the number of unpaired electrons in the atom of the element having atomic number 16. (iii) Which of the following ions does not obey Bohr's atomic theory? He^(2+),Li^(2+),B^(3+),Be^(3+) .

Anything that influences the valence electrons will affect the chemistry of the element. Which one of the following factors does not affect the valence shell? (A) Valence principal quantum number (n). (B) Number charge (Z). (C) Nuclear mass (D) Number of core electrons.

First ionisation energy of elements increases with atomic numbers of the elements in a period-why cite an exception.

What is the maximum number of atoms in a hcp crystal structure of an element ?

What is the maximum number of atoms in a bcc crystal structure of an element ?

What is the number of elements in the 3rd period of the modernn periodic table?