Question

(i) How does the melting point of lithium compare with that of caesium?

plz give the answer fast​

Answer 1

Answer:

The alkali metals have low melting points. Lithium melts at 180.5 °C (356.9 °F); cesium melts at just 28.4 °C (83.1 °F).

As the radius of atoms get larger down the group, you could say that the force holding them together is spread over the greater area and hence, the metal cations are more weakly bonded. And coming back to my first point, when the bonding is weaker, the metal's melting point will decrease.

The alkali metals share similar physical and chemical properties.

Physical properties

The alkali metals:

are soft (they can be cut with a knife)

have relatively low melting points

The alkali metals also have low densities. They are low enough for the first three (lithium, sodium and potassium) to float on water.

Lithium, Li180°C

Sodium, Na98°C

Potassium, K63°C

Rubidium, Rb39°C

Caesium, Cs