State how density and melting points of elements varies across a period and down a group.

State the general trend in periodicity in properties of oxides, hydroxides, oxy-acids and hydrides of compounds of elements across a period and down a group.

Define valency. How does it change across a period and on going down a group?

How does reducing power of elements vary in group 1 ?

State the reason for periodicity of elements in periods and groups.

What happens to number of valence electrons in atoms of elements as we go down a group of the periodic table ?

With reference to group 1 [IA] of the periodic table - fill in the blanks with the correct word: The elements are _____ [light/heavy]. __________[metals/non-metals] since their atomic size is _______ [large/small]. The energy binding the atoms is ______ [high/low] and hence the elements have [high/low] melting points. The melting points of the elements ______ [increases/decreases] down the subgroup. The electropositive character._______ [increases/decreases] down the subgroup and the elements are strong _______ [reducing/oxidizing] agents. The element with electronic configuration 2,8,1 will have _______ [higher/lower] electronaffinity and _______ [smaller/larger] atomic size than the element with electronic configuration 2,1.

How do melting and boiling points vary in a (a) period and (b) group in periodic table?

How do the Melting and boiling points property vary on moving down the group 13?

What is the difference between the molecules of soaps and detergents, chemically ? Explain the cleansing action of soaps. or How many groups and periods are there in the modern periodic table ? How do the atomic size and metallic character of elements vary as we move : 1. along the group 2. along the period :

Explain the trend in general of ionisation potential of elements : on moving down a group. Give reasons for the change in the periodic trend in each case.