What is dry ice?

The triple-point of water is a standard fixed point in modern thermometry.Why? What is wrong in taking the melting point of ice and the boiling point of water as standard fixed points (as was originally done in the Celsius scale)?

What is a shunt? What is its use?

What is Carnot engine and what is its efficency?

What is root cap? What is its function?

What is sarface tension? What is its unit?

What is surface energy? What is its unit?

What is hydrogenation ? What is its industrial application?

Mention one use of dry ice.

What is the melting point of ice?