What things sink?

* Metals: Most metals are denser than water, so they will sink. Some examples of metals that sink include iron, steel, copper, and lead.

* Rocks: Rocks are also typically denser than water, so they will sink. Some examples of rocks that sink include granite, sandstone, and limestone.

* Soil: Soil is made up of a mixture of minerals, organic matter, and water. When the density of soil is greater than the density of water, it will sink.

* Sand: Sand is made up of small grains of rock and minerals. When the density of sand is greater than the density of water, it will sink.

* Gravel: Gravel is made up of larger pieces of rock and minerals. When the density of gravel is greater than the density of water, it will sink.

* Wood: Wood is less dense than water, so it will float. However, if wood is wet, it can become denser and sink.

* Ice: Ice is less dense than water, so it will float. However, if ice is very thick, it can become denser and sink.

* Oil: Oil is less dense than water, so it will float.

* Gas: Gas is less dense than water, so it will rise to the surface.