Molecular Scrabble

The game is played on an hexagonal grid board using tiles with a periodic element index fill-painted on one side. To begin, each player blindly chooses 7 tiles for their bouquet.

Turns consist of creating a new molecule or modifying an existing molecule, by adding or inserting tiles. Tiles already on the board may be moved or removed to accomodate the change.

Unlike word Scrabble, a new molecule can be started anywhere. Adjacent tiles in a molecule indicate an atomic bond (actual geometry is otherwise ignored).

At the end of a turn, all molecules on the board must be viable.

Scoring:
• +points: tiles played plus existing tiles in the molecule which haven't been moved;
• -points: removed tiles.
As in word Scrabble there are multiplier squares (err "hexes"), valid for the first covering by a tile.

The face value of the tiles is a rough reciprocal of the element's affinity to formation. (Noble gases have a higher value if they're in a molecule, rather than played in their monatomic state.)

At the end of a turn, the player takes enough tiles from the bag to bring his/her bouquet up to the minimum of 7 pieces. (Since tiles removed during play are put into the bouquet the player may already have 7 or more pieces)

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Variation: Entropic Scrabble - as above, but scoring is based on energy of formation.