Cambridge Secondary (7-9). Stage 9. MCE Science. Student Book - Unit 4: The Structure of the Atom and the Periodic Table - Question 40

Rubidium is in Group 1 below potassium on the Periodic Table. Use what you know about the trends in Group 1 to predict what you think the melting and boiling points are of rubidium.

For comparison, the book gives potassium: melting point 63°C; boiling point 759°C.