Home >> Science & Nature >> Science

Can a Hard-Boiled Egg Float in Saltwater?

While a hard-boiled egg sinks in plain water, it floats in saltwater. An egg has a liquid center that turns solid when boiled. Conduct an experiment to show the differences in density between a hard-boiled egg, regular plain water and saltwater. If you attempt to float something in water and it sinks, it is more dense than the water, while if it floats, it is less dense.

Plain Water and Raw Egg
- Fill an empty cup with 2 cups of plain water. Drop a raw egg in the water to determine whether it is more or less dense than the water. It will sink because a raw egg is more dense than plain water.
Saltwater and Raw Egg
- Add a few spoonfuls of salt to the water. Try four or five to start. Drop your egg in the water to watch it float. This will occur because the salt makes the water more dense than the egg.
Hard-Boiled Egg in Plain Water
- Repeat your experiment using a hard-boiled egg instead of a raw egg. The hard-boiled egg will still sink in the water just like the raw egg because, even though the egg is hard-boiled and less dense than a raw egg, it is not less dense than water.
Hard-Boiled Egg in Saltwater
- Add 1/4 cup of salt to another 2 cups of water, then drop the hard-boiled egg into the water to see it float. It will rise to the top to float, similar to the raw egg.

Science