Question 6
Going from top to bottom down a group, what happens to the first ionization energy?
The right answer is the one marked above.
It decreases. In group I: lithium 519, sodium 495, potassium 418.
Take care not to mix the two directions up. Across a period, left to right, the ionization energy rises. Down a group it falls. They are different questions about the same table, and the answers point opposite ways.