The first systematic classification of elements was done by

An allotrope of carbon which has a spherical molecule made of 60 carbon atoms covalently bonded together is called:

When an element can exist in more than one structural form in the physical state, it is:

Materials that can return to their old shape after stretching are called:

Duralumin consists of aluminium and:

Hot metal at high temperature is allowed to cool slowly, producing a large grain size. This process is called:  

The number of outer electrons in Noble gases are:

A borosilicate glass among the following:

The electrostatic force of attraction between atoms is called

Metallic bond is due to the presence of