The electronic configuration of an element is 1s²,2s²,2p⁶,3s²,3p³.  What is the atomic number of the element, which is present just below the above element in the periodic table ?

In crystals of which of the following ionic compounds would you expect maximum distance between centres of cations and anions ?

The horizontal columns in a periodic table are known as

Elements could be arranged in a group of three called triad in such a way that the middle element had an atomic weight almost the average of the other two,this was found by 

The fourteen elements from Th to Lr are known as

The element with the atomic number 118, will be

 Arrangement of all the known elements,based on a certain law known as periodic law,in a manner that the elements with similar properties fall in the same vertical column called a group is a

The fourteen elements from Th to Lr are known as

 The most fundamental property of an element is the atomic number and not the atomic mass and is responsible for its physical and chemical behaviour,this was showed by 

The ionisation of hydrogen atom would give rise to