Question

how does a lithium cation compare to a lithium atom?
the cation is larger.
the cation has the same radius.
the cation is smaller.
the cation has the same charge.

Explanation:

A lithium cation is formed when a lithium atom loses an electron. Losing an electron reduces electron - electron repulsion and the remaining electrons are pulled closer to the nucleus, making the cation smaller.

Answer:

The cation is smaller.