Question

The following questions refer to the periodic table. 

1) Name the first and the last element in period 2. 

2) What happens to the atomic size of elements moving from top to bottom of a group? 

3) Which of the elements has the highest electron affinity among the halogens? 

4) What is common feature of the electronic configurations of the elements in group 16?

Answer 1

1) The first and the last elements of 2nd period or Lithium and Neon.

2) The atomic size decreases as we move from top to bottom in a group because there is an addition of shell each time as we move down the group. 

3) Chlorine has the highest electron affinity. We know as move from top to bottom the electron affinity values decrease. But due to small size of fluorine there would be more electron-electron repulsions, if we add electron. So Chlorine has more electron affinity. 

4) All these have same general outermost electronic configuration that is ns² np⁴.