Cambridge Secondary (7-9). Stage 9. MCE Science. Workbook - Unit 4: The Structure of the Atom and the Periodic Table - Question 22

Complete the paragraph.

The elements lithium, sodium and potassium all belong to Group ______ of the Periodic Table. They are in this group because they all have ______ electron in their outer ______. Down this group, the melting and boiling points ______, and the reactivity ______.