Can a thermos keep drinks cold?

Yes, it slows heat flow both ways

Thermos Flask Quiz: Vacuum Walls That Keep Drinks Hot

This thermos flask quiz pours a hot drink on a cold day. Play 10 interactive questions on James Dewar's vacuum flask of 1892, the German company Thermos founded in 1904, a vacuum that blocks conduction and convection, silvered walls that reflect radiation, the stopper as the weak spot, why the same flask keeps ice cold and how Thermos became a generic word.

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🎯 Daily Trivia Challenge • 🧠 10 Questions • ⏱️ 150 Seconds

Question 1 / 10 Time: 150s

Who
Who invented the vacuum flask in 1892?
Why
What did Dewar first use it for?
Company
When was the company Thermos founded in Germany?
Vac
What does the vacuum between walls stop?
Silver
Why are the inner walls silvered?
Weak
Where does most heat escape?
Cold
Can a thermos keep drinks cold?
Generic
What happened to the word thermos in the US?
Lab
What is a vacuum flask called in labs?
Pre
What helps a thermos keep drinks hotter?

Explanations: answer key for all 10 questions

Q1: Who invented the vacuum flask in 1892?
Answer: James Dewar
He was a Scottish scientist.
Q2: What did Dewar first use it for?
Answer: Keeping chemicals cold
He studied very low temperatures.
Q3: When was the company Thermos founded in Germany?
Answer: 1904
Its name comes from Greek for hot.
Q4: What does the vacuum between walls stop?
Answer: Conduction and convection
There are almost no molecules to carry heat.
Q5: Why are the inner walls silvered?
Answer: To reflect heat radiation
Radiation can cross a vacuum.
Q6: Where does most heat escape?
Answer: Through the stopper
It is the weakest part.
Q7: Can a thermos keep drinks cold?
Answer: Yes, it slows heat flow both ways
Heat cannot get in easily.
Q8: What happened to the word thermos in the US?
Answer: It became a generic term
A 1963 court ruling decided it.
Q9: What is a vacuum flask called in labs?
Answer: A Dewar flask
Used for liquid nitrogen.
Q10: What helps a thermos keep drinks hotter?
Answer: Preheating it with hot water
Warm walls absorb less heat.

Two Walls and Nothing Between

In 1892, Scottish scientist James Dewar invented the vacuum flask to keep chemicals cold while studying very low temperatures. In 1904 a German company named Thermos, after the Greek word for hot, began selling flasks for drinks. In labs, vacuum flasks are still called Dewar flasks and hold liquid nitrogen.

A flask has two walls with a vacuum between them. With almost no molecules to carry heat, the vacuum blocks conduction and convection. Radiation can cross a vacuum, so the walls are silvered to reflect it. The stopper is the weakest part, where most heat escapes.

Because a flask slows heat flow both ways, it keeps cold drinks cold as well as hot drinks hot. Preheating it with hot water helps keep drinks hotter. In the United States, a 1963 court ruling decided that thermos had become a generic term.

What This Quiz Teaches

Science fans will enjoy these questions.

Who invented the flask
How the vacuum works
Why walls are silvered
Where heat escapes
How the name became generic

Did You Know?

Steel flasks replaced fragile glass.
Food jars use the same idea.
Some flasks keep heat for a day.
Tea can stew if left too long.
Dewar also studied liquid hydrogen.