The Fascinating Game of Chemical Formulas.
The idea of the game is to arrange cards as to form compounds letting each card represent an atom. Each player must have the correct number and kinds of cards for the compound being made, i.e. H2O - must have one oxygen card and two hydrogen cards.
Game is similar to rummy. Players dealt 9 cards. One draw pile and one discard pile (starting with one card up.) Players draw one card (from either pile) and discard one card on turn. Play continues until one player has all cards in had made into compounds. Player lays all cards down and calls out "Precipitate."
Every player gets score for cards made into compounds, points increasing for number of cards per compound. Player who called "Precipitate" gets 10 points. Game played until one player has 100 points.
Game can be played with any number of players (solitaire directions included) but best with 2-6.