The inert gas which lies in third period is 

The number of electrons present in the valency shell of a halogen is:

Which of the following sets of atomic number belong to that of alkali metals?

The amount of energy released when one or more electrons is added to the neutral atom is 

The non-metallic character of the elements from left to right across the period

Eka-aluminium and Eka-silicon are known as 

The electronegativity of an element from left  to right across a period

Element 'A' has electronic configuration 2, 7; 'B' has electronic configuration 2, 8, 5 and 'C' has electronic configuration 2, 8, 7. Which two elements will exhibit similar chemical properties?

An element in period-3 whose electron affinity is zero.

The longest period of periodic table is