Periodic Table is defined as, "A table of the chemical elements arranged in order of atomic number, electron configuration, and recurring chemical properties; usually arranged in rows, so that elements with similar atomic structure (and hence similar chemical properties) appear in vertical columns." A good definition for a younger student is, "The periodic table is a way of listing the elements. Elements are listed in the table by structure of their atoms. This includes how many protons they have as well as how many electrons they have in their outer shell. From left to right and top to bottom, the elements are listed in order of their atomic number, which is the number of protons in each atom." (This definition and more information for kids available here.)
Students are typically introduced to the periodic table around 5th or 6th grade. As always, best practice is to pair a tactile periodic table with the digital periodic table to help the student transition from tactile materialsl to digital materials. One advantage of the digital periodic table is that more information can be provided in a very small space. A brailled/tactile version containing the same information would be huge! The digital version also has embedded links to detailed information about each element. When introduced to the digital periodic table on a touch screen device - such as an iPad - the student should be encouraged to first explore the periodic table by dragging his finger across the screen. Students should pay attention to and learn where various elements are physically located on the table!
On their website, Web Elements has a periodic table that is fully accessible with screen readers. Access the Web Elemenents periodic table here. This periodic table is correctly formated as an accessible table, meaning that a screen reader will read the row and column headers and will announce when the VoiceOver focus moves to a new row or a new column. The screen reader will initially announce both the row and column numbers. After that initial announcement, the screen reader will only announce the new column number or the new row number. When accessing this periodic table with an iPad running VoiceOver, set the rotor to Rows. Swipe up or down will now navigate up or down through the current column. When you swipe down and move down to the next row, VoiceOver will announce the new atomic number then the new row number. Sequential right swipes will move through each item in that square, and then move right to the next square/element. When moving to the next square/element, VoiceOver will announce the new atomic number and then the new column number. Announcing the row and column headers is beneficial in helping the student understand where he is within the periodic table. Double tap on an element to open a link for detailed information about that element.
Note: The VoiceOver focus must be on table in order to show up in the rotor.
The periodic table is an excellent way to teach and/or practice tech skills, including navigating through a table using the rotor set to Rows and developing spatial concepts/mental mapping skills. Note: All screen readers have similar ways to navigate accessible tables. Touch screen devices have the advantage of being able to drag your finger around the screen to which provides physical spatial relationship information.