Definition: Given scientific fact as input, generate the question from this fact such that it can be answered from the input.
Input: Elements below the second period, such as silicon, do not form n bonds as readily as second-period elements, and when they do form, they are weaker than those formed by second-period elements.
Output:
Elements below the second period, such as silicon, do not form what as readily as second-period elements, and when they do form, they are weaker than those formed by second-period elements?