In this task, you are given a question and an answer, you would be asked to create the sentence based on the Question-Answer provided. It should be contained within the Question-Answer provided.

[Q]: Question: 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? Answer: n bonds
[A]: 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.

[Q]: Question: What do you call sound that has a wave frequency higher than the human ear can detect? Answer: ultrasound
[A]: You call sound that has a wave frequency higher than the human ear can detect ultrasound.

[Q]: Question: What is it called when one or more ending digits are dropped to get the correct number of significant figures? Answer: rounding
[A]:
Rounding is when one or more ending digits are dropped to get the correct number of significant figures.