Three squares labeled “Ru” = red up and three labeled “Rd” = red down

Three squares labeled “Bu” = blue up and three labeled “Bd” = blue down

Three squares labeled “Gu” = green up and three labeled “Gd” = green down

In this activity, you will be making five sets of combinations. Each square can only be used once in making a set of combinations. Each combination in a set must be unique.

Mirror images are not unique combinations.

Record the number of unique combinations you could make in the space after the combination description by writing out the particle combination formula.

Example: Ru Bu Gu is a unique combination. So Gu Bu Ru, being the mirror image is not unique.

Set One
How many combinations of three squares can you make if each combination must contain three colors of squares?






Set Two
How many combinations of three squares can you make if each group must have two “up” squares and one “down” square?






Set Three
How many combinations of three different color squares can you make if each group must have two “down squares” and one “up” square?






Set Four
How many combinations of three squares can you make if each group must have one red, one green, one blue, two “up” squares and one “down” square?






Set Five
How many combinations of three squares can you make if each group must have one red, one green, one blue, two “down” squares and one “up” square?






When you have finished making the arrangements, answer the following questions:

If an “up” square has an elementary electric charge of plus two thirds and a “down” square has a charge of minus one third, what would be the net charge of the combinations in Set Four?

What would be the net charge of the combinations in Set Five?