Question

analyze and interpret the data in the table below. which prediction about the alkali metals data is true? melting point (°c) francium? 28.4 cesium 39.3 rubidium 63.4 potassium 97.8 sodium 180.5 boiling point (°c) francium? 671 cesium 688 rubidium 759 potassium 882 sodium 1342 radius (pm) francium? 265 cesium 248 rubidium 227 potassium 186 sodium 152 francium will have the lowest melting point and the largest radius of all the alkali metals. francium will have the highest melting point and the largest radius of all the alkali metals. francium will have a lower boiling point and a smaller radius than lithium. francium will have a higher melting point and a lower boiling point than the other alkali metals.

Explanation:

As we move down the group of alkali - metals, the atomic radius increases due to the addition of new electron shells. The melting and boiling points generally decrease because the metallic bonds become weaker with larger atomic sizes. Francium is at the bottom of the alkali - metal group. So, it will have the largest radius among the alkali metals and the lowest melting point among them as well, based on the trends shown in the table for other alkali metals (lithium, sodium, potassium, rubidium, cesium).

Answer:

Francium will have the lowest melting point and the largest radius of all the alkali metals.