We have been busy loving on our kids and spending special time with my mom. One of the things we did was a great trip to the beach.
This was our first real trip to the beach. We had taken the boys to the beach for the day, but never actually stayed there. Unfortunately, we had double red or red flags most of the time. We tried to make the best of it in this inlet.
My little guy was mesmorized by the pull of the ocean and my bigger little guy was on a critter search, but wasn't too thrilled when we found a crab.
Now that we are back I want to capture some of that enthusiasm and start our science discovery back again. This is a simple experiment that you can go into a lot of detail about or just a little to explain.
You put two eggs into two different solutions and observe the egg floating in the salt water solution. The reason the egg floats is density. The density of the two eggs (or you can use a single egg in two different solutions) will remain the same, but as you add salt (which has mass) to the bowl of water without changing the volume of water (the salt will dissolve in the water) the density of the water increases.
The math equation for this is density = mass/volume. If math isn't your thing, a conceptual definition of density is how tightly the particles in a substance are packed together. In order for something to float it has to be less dense than the liquid it is in.
This also explains why it is easier to float in the ocean versus a chlorinated pool. The saltwater has more density and it can lift/carry/float you more easily.
Since this experiment introduces the idea of density there is a lot more you can do with density. You might pick the detail depending on the age and interest of your child. To add an interesting twist you could use saltwater in the sink or float experiments or add varying amounts of salt. Explore! Kids love to experiment. Here are a few ideas to jump off of: