flask

Everyday

1. A flask is a container that keeps drinks hot or cold, also called a vacuum flask or Thermos. tree →
2. In science, a flask is a glass container with a narrow neck, used in experiments. tree →
3. A flask can also be a small flat bottle for carrying a drink in a pocket. tree →

In the lessons

In everyday life families take a flask of tea or soup on a picnic or walk; in science labs, conical flasks hold liquids for experiments. In science lessons pupils learn how a vacuum flask stops heat moving in or out. Phrases: «a flask of tea», «a conical flask», «a vacuum flask».

Examples

• Grandpa poured hot tea from his flask. tree →
• Take a flask of soup on the cold walk. tree →
• The scientist swirled the liquid in the flask. tree →
• A vacuum flask keeps drinks hot for hours. tree →
• The flask also keeps cold drinks cold. tree →
• Use a conical flask for this experiment. tree →
• My water flask fits in my school bag. tree →
• He was about to take a drink from a flask. tree →

Note

Countable. A vacuum flask works because there is almost no air between its two walls, so heat cannot move through easily. Safety: glass flasks break; handle them with care and wear goggles in experiments.