What observations are made when a small piece of sodium is dropped into cold water?

When a small piece of sodium is dropped into cold water, the following observations are typically made:

1. The sodium immediately starts to fizz and bubble as it reacts with the water.
2. The reaction produces hydrogen gas, which can be seen as bubbles rising to the surface of the water.
3. The sodium may move around rapidly in the water due to the release of hydrogen gas.
4. The water may become warm as the reaction between sodium and water is exothermic.
5. A white trail of sodium hydroxide may form in the water as a byproduct of the reaction.

- The sodium piece starts moving rapidly on the surface of the water with a hissing sound.
- A yellow flame is produced.
- A colourless gas is also evolved which is hydrogen gas.
- The sodium hydroxide solution is formed.