Question

When the elements in group 1 are considered in order from top to bottom, each successive element at standard pressure has

Answer 1

When the elements in group 1 are considered in order from top to bottom, each successive element at a standard pressure has a lower melting point and boiling point. This is because melting and boiling points decrease when the increasing atomic number. The correct answer will be D. 

Answer 2

Answer is: d. a lower melting point and boiling point.

Alkaline metals are lithium, sodium, rubidium, potassium, cesium and francium.

Bond between these elements is metallic bond.

Both the melting and boiling points decrease down the group 1, because the decrease in the strength of each metallic bond.

From top to bottom, atomic radius increase and the distance between the nucleus and delocalized electrons increases, so metallic bond is weaker (attractions fall).

Metallic bond is formed between electrons and positively charged metal ions.