Answer :
To analyze and interpret the data regarding the alkali metals, let's take a closer look at the trends displayed in the table for elements like Lithium, Sodium, Potassium, Rubidium, and Cesium.
1. Melting Point Trends:
- Start from Lithium and move down the group to Cesium:
- Lithium: 180.5°C
- Sodium: 97.8°C
- Potassium: 63.4°C
- Rubidium: 39.3°C
- Cesium: 28.4°C
- We can observe that the melting point decreases as we progress from Lithium to Cesium.
2. Boiling Point Trends:
- Similarly, from Lithium to Cesium:
- Lithium: 1342°C
- Sodium: 882°C
- Potassium: 759°C
- Rubidium: 688°C
- Cesium: 671°C
- The boiling point also decreases as we move down the group, but not as sharply as the melting points do.
3. Radius Trends:
- Again from Lithium to Cesium:
- Lithium: 152 pm
- Sodium: 186 pm
- Potassium: 227 pm
- Rubidium: 248 pm
- Cesium: 265 pm
- The atomic radius increases as we go down the group.
Prediction for Francium:
- Based on these trends, we can predict the characteristics of Francium:
- Since the melting points decrease down the group, it is reasonable to expect that Francium, being below Cesium on the periodic table, will have the lowest melting point among the alkali metals.
- With the atomic radius increasing down the group, Francium is expected to have the largest atomic radius.
Therefore, the correct prediction for Francium based on these observed trends is: Francium will have the lowest melting point and the largest radius of all the alkali metals.
1. Melting Point Trends:
- Start from Lithium and move down the group to Cesium:
- Lithium: 180.5°C
- Sodium: 97.8°C
- Potassium: 63.4°C
- Rubidium: 39.3°C
- Cesium: 28.4°C
- We can observe that the melting point decreases as we progress from Lithium to Cesium.
2. Boiling Point Trends:
- Similarly, from Lithium to Cesium:
- Lithium: 1342°C
- Sodium: 882°C
- Potassium: 759°C
- Rubidium: 688°C
- Cesium: 671°C
- The boiling point also decreases as we move down the group, but not as sharply as the melting points do.
3. Radius Trends:
- Again from Lithium to Cesium:
- Lithium: 152 pm
- Sodium: 186 pm
- Potassium: 227 pm
- Rubidium: 248 pm
- Cesium: 265 pm
- The atomic radius increases as we go down the group.
Prediction for Francium:
- Based on these trends, we can predict the characteristics of Francium:
- Since the melting points decrease down the group, it is reasonable to expect that Francium, being below Cesium on the periodic table, will have the lowest melting point among the alkali metals.
- With the atomic radius increasing down the group, Francium is expected to have the largest atomic radius.
Therefore, the correct prediction for Francium based on these observed trends is: Francium will have the lowest melting point and the largest radius of all the alkali metals.
