Mendeleev activity: how to use the activity

When the game starts the 63 elements known to Mendeleev are shown as cards arranged at random on a grid. The symbol and relative atomic mass are always displayed, and holding your mouse pointer over an element will reveal some of its properties in a 'status area' at the bottom left of the playing area. You can:

Re-arrange the elements by dragging them to new positions

There are two ways of doing this depending on the Drag mode. To move one element at a time select one at a time. Elements may be picked up singly and moved freely to any location on the grid, so that their order is not necessarily preserved . By contrast, in keep together mode elements are moved in continuous 'chains' in such a way as to preserve their order. A chain is all the elements following the one clicked and ending with the first blank.

During a drag green squares indicate where the elements will finish. Red squares indicate an illegal move and are accompanied by an explanatory message in the status area.

Arranging the elements in relative atomic mass order

Press the Sort by RAM button. Any undiscovered elements you have added will be sorted provided you have assigned them a relative atomic mass (see below).

Introduce 'undiscovered' elements

To do this drag from the undiscovered element 'pile' at the bottom right of the playing area, releasing at the appropriate place. These elements are given the symbol "?". You can assign a relative atomic mass to an undiscovered element by typing a value into the text box and pressing set RAM - this must be done before the element is added. The advantage of doing this is that they can then be sorted as described above. Once added undiscovered elements behave as regular elements. To remove an undiscovered element drag it back to the undiscovered element pile.

Press save at any point to save the current arrangement, and restore to restore that arrangement at a later time. Press reset to start again. For more detailed instructions and some tips on strategy use the Hints for students and Instructions for teachers above.