group 18 elements part 1

The element having highest electron gain enthalpy (with sign) among group 18 elements are:

The group 18 element placed in period 3

Why group -1 elements are called alkali metals ?

Group 1 elements are known as _____

(a) What is a group in the periodic table? In which part of a group would you separately expect elements to have (i) the greatest metallic character (ii) the largest atomic size? (b) In what respects do the properties of group 1 elements differ from those of group 17 elements? Explain with examples by taking one element from each group. (c) From the standpoint of atomic structure, what determines which element will be the first and which the last in a period of the periodic table? (d) Explain why, the properties of elements are repeated after 2,8,18 and 32 elements in the periodic table.

(a) What is the usual number of valence electrons and valency of group 18 elements of the periodic table? (b)What happens to the number of valence electrons in the atoms is elements as we go down in a group of the periodic table?