Question

The correct order of density of alkali metals is:

• A.
• B.
• C.
• D.

Answer 1

The correct option is A

As we go down a group - density increases generally. However, there is a notable exception in potassium, which is less dense than sodium. Simply put, in the case of potassium the increase in shell size outweighs the pull of the core on the outer shell electron and so potassium is less dense than sodium.