The atomic numbers of four element P,Q,R and S are 6,10,12 and 17 respectively. Which two elements can combine to form a covalent compound?

The atomic numbers of four elements A,B,C and D are 6,10,12 and 17 respectively. Which two elements combine to form a covalent compound ?

The atomic numbers of four elements, A,B,C and D are 6,8,10 and 12 respectively. The two elements which can react to form ionic bonds (or ionic compounds) are:

The atomic numbers of four elements A,B,C and D are 12,13, 15 and 3 respectively. The element which cannot form a cation is :

The atomic numbers of four elements P,Q,R and S are 6,8,14 and 16 respectively. Out of these, the element known as metalloid is

The atomic number of elements P, Q, R, S and T are given. Which two elements are chemically similar?

The atomic numbers of two elements A and B are 11 and 12 respectively. Which element exhibits highest metallic property ? Why ? Write the molecular formula of the compounds formed when these elements combine with the element 'Z' having atomic number 8.