floating and sinking

In Junior Infants we did some floating and sinking in science. The children predicted that some things would float and others would sink. We got two dice. A small plastic dice sank. A large foam one covered in plastic floated. A pebble, a crayon and a pencil pointer sank. A counter from connect up 4, a pencil and a bottle cork floated. The children determined that if something was heavy it sank.

To explore this further I asked one pupil to put a can of regular Coke into a drum of water. It sank. See picture. We then put in a Diet Coke. It floated. The regular Coke was heavier because it had sugar in it. The Diet Coke didn’t.

For fun we looked at Orbeez. Orbeez are superabsorbent polymers that grow to more than 100 times their volume when placed in water. And just what are polymers, you ask? Excellent question! Polymers are several molecules joined together and they grow when the water is absorbed in the spaces between the molecules. Apparently, polymers were invented way back in the ’60s to irrigate crops during droughts. Who knew! But parents better know polymers as the tiny beads inside diapers. That’s right, Orbeez are basically just colorful diaper pellets.

See pictures attached of Orbeez in a dry state and then with water absorbed into them. The children really enjoyed playing with these.