To teach the periodic table effectively you must make sure your students have the proper background information to begin learning about it, and also make your lesson an interesting exploration of the tool they will use most often during the rest of the year. The traditional memorization approach to teaching the periodic table is often the least effective method because it doesn’t help students relate the concept of organization within the periodic table to atomic structure. This will decrease their overall understanding of both subjects. There may be some memorization work involved, but the more you can offset that with interesting and challenging inquiry-type activities, the more the kids will stay engaged and actually learn the material.
By the time your students have reached eleventh grade they have, hopefully, been exposed to the periodic table at least once or twice in previous science classes. A simple pre-assessment to determine if your students know the difference between atomic mass and atomic number on the squares of the periodic table will give you a good idea of where you need to start. If they can’t already read the squares on the periodic table, have them pick an element and re-create the square from the periodic on one side of a large index card and research some properties of the element and write those on the other side. This activity is a good hands-on way to teach them how to read the squares on the periodic table and you can use the cards later to illustrate how families of elements share properties by using the cards to build a periodic table in the classroom and having the kids investigate the properties of each element family.
Once they can read the squares, it is time to teach them about how the periodic table is organized. A great lab activity for this topic can be found in chapter five of Ian Guch’s incredible book 24 Lessons That Rocked the World (his entire website is an incredible resource for high-quality, free chemistry teacher resources). In this activity students are given a set of random objects and asked to organize them according to one property (i.e. color, shape, etc.). Then they build a periodic table for their objects and present it to the class. This lesson plan involves using an inquiry activity to help students learn about the periodic table by exploration rather than rote memorization. Using an inquiry-type activity like this to teach students about the different ways the periodic table is organized will relate this information to some of the key concepts about atomic structure they have already learned, whereas a strictly lecture approach generally leads to students simply memorizing the pattern of organization in the periodic table.