Create baggies for 5 centers and have them sort by size, shape, color, weight, and texture. I did not do buoyancy in this sort because I do a separate hands on experiment with buckets of water and objects.
I have 5 centers going at a time. I give each group a baggie and they have to work together to sort the picture cards. When time is up, they have to explain to the class why they sorted the items they way that they did. I like to see the different rational that they use when sorting.