Compare and contrast the arrangement of elements in Mendeleev's periodic table and the Modem periodic table.

The positions of three elements A, B and C in the periodic table are shown below:

(a) State whether A is a metal or non-metal.

(b) State whether C is more reactive or less reactive than A.

(c) Will C be larger or smaller in size than B?

(d) Which type of ion, cation or anion, will be formed by element A ?

Nitrogen (atomic number 7) and phosphorus (atomic number 15) belong to group 15 of the periodic table. Write the electronic configurations of these two elements. Which of these will be more electronegative ? Why?

How does the electronic configuration of an element relate to its position in the modem periodic table ?

In the modem periodic table, calcium (atomic number 20) is surrounded by elements with atomic numbers 12, 19, 21 and 38. Which of these have physical and chemical properties resembling calcium ?