Question

1. analyze and interpret the data in the table below. which prediction about the element francium is true?

alkali metals data

element	melting point (°c)	boiling point (°c)	radius (pm)
sodium	97.8	882	186
potassium	63.4	759	227
rubidium	39.3	688	248
cesium	28.4	671	265
francium	?	?	?

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:

Step1: Observe trends in data

As we move down the alkali - metal group from lithium to cesium, the melting point decreases (180.5°C for Li to 28.4°C for Cs) and the atomic radius increases (152 pm for Li to 265 pm for Cs).

Step2: Predict for francium

Francium is below cesium in the alkali - metal group. So, following the trends, it will have the lowest melting point and the largest radius among all alkali metals.

Answer:

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