As the air molecules move through the valve they have friction as they hit the walls, and its this friction that causes it to heat up.
Answer:
1.37cm
Explanation:
It's less than 1.4cm but more than 1.3cm. It's also more than 1.35cm so I guess the best answer would be 1.37cm or round up to 1.4cm
The answer is in the attachment below:
Answer:
Chemical change.
Explanation:
When it is heated it decomposes into mercury and oxygen gas. The mercury oxide reactant becomes the silver color of mercury. Hence, a color change can be noticed throughout the reaction.