Question

A flask is heated from 30°C to 100°C. X is the initial level of water. When heated, water level falls from X to Y and then rises to Z. Why?​

Answer 1

Explanation:

This is because the glass gets hot first and so expands and the volume of the beaker therefore increases. This means that the water level will drop. Then the water starts getting hotter, it expands more than the glass and so the water level rises.