pick from the following.
[1]. chemical trends;
[2]. gravity trends;
[3]. acoustic trends;
[4]. periodic trends;

Q: Snippet 2: one of the reasons the periodic table is so useful is because its structure allows us to qualitatively determine how some properties of the elements vary versus their position on the periodic table. the variation of properties versus position on the periodic table is called what? A:
Answer:
[4].