# The Ultimate Thermos Quiz

By: Staff

4 Min Quiz

Image: refer to hsw

You're going on a picnic and you want to take along a hot drink, so you put it in a thermos so it will stay hot. Or maybe it's a hot day and you put a cold drink or water in a thermos to keep it cold. Have you ever wondered how a thermos can keep things both hot or cold? Take this quiz to see how much you know about your thermos.

# What does the concept of thermodynamics refer to?

Thermodynamics refers to heat transfer, where heat naturally moves to a cooler place to create an even temperature.

# What is heat anyway?

When atoms move they create heat.

# What factor effects the amount of heat created?

The speed the atoms are moving at determines how much heat is produced. The faster they go, the more heat is produced.

# At what temperature is there no atomic movement?

At the temperature of absolute zero there is no atomic movement.

# How is heat transferred?

When atoms collide they transfer heat. It's a bit like billiard balls colliding. When one ball hits another, the second ball picks up momentum from the first ball.

# What does the process of conduction refer to?

Conduction refers to the transfer of heat through atom collisions.

# Which of the following materials is a good conductor?

Metal is a good conductor, which is why, if you heat the end of a metal rod, the other end will quickly become hot.

# Infrared radiation is a form of _____?

Infrared radiation is a form of light, but it is outside the spectrum visible to the human eye.

# What color best absorbs infrared radiation?

Black objects best absorb infrared. The absorption of infrared causes an increase in atomic motion, leading to a rise in temperature. So if you want to stay cool, it's best to wear light-colored clothing!

# How much of the sun's energy that reaches the Earth is infrared radiation?

About half of the sun's energy that makes it to Earth is infrared radiation, which we experience as warmth. The rest is visible light.

# Which of the following are affected by the process of convection?

Convection is the cycle of warm particles rising while cooler particles fill their space, heat up, and rise as the cycle continues. Convection affects both liquids and gases since, when these media get warm, the warm particles rise above both.

# A good thermos will _____the transfer of heat by conduction, radiation and convection.

The purpose of a thermos is to reduce the transfer of heat.

# Which method does a thermos use to reduce heat?

A thermos is built based on the principle of insulation.

# A good way to make your own thermos would be to surround a jar with which of the following?

Foam is a good insulator because both the plastic in it and the air trapped in it are poor conductors and because convection cannot take place effectively since air in the foam is broken into tiny bubbles.

# Why is a vacuum a better way of insulating?

In a vacuum there are almost no atoms, which means there cannot be conduction or convection -- ideal in a thermos. Although it is almost impossible to make a perfect vacuum with zero atoms, a good thermos can get close.

# Inside a thermos there is a glass envelope which is surrounded by a vacuum. The glass is silvered, making it like a _____?

Silvered glass acts as a mirror, reflecting infrared radiation away.

# Why do things in a thermos lose their heat?

The heat loss in the imperfect vacuum is not significant compared to the heat lost through the cap. Also, the glass meets the walls at the top of the flask , creating a conduction path.

# How does a thermos know if you have hot or cold food inside?

It doesn't know -- or care. It stops heat transfer, be it inside or outside the flask.

# It is not recommended to encase the glass center of a thermos in _____.

Although you might think bubble wrap would help with insulation, you need something sturdy, like metal or plastic, to protect the fragile glass inside.