Q 01/05

At what Fahrenheit reading does water boil at sea level?

A) 32 °F

B) 100 °F

C) 212 °F

D) 451 °F

Answer · why

C) 212 °F

212 °F holds only at sea level: the boiling point falls by just under 1 °F for every 500 feet climbed, which is why food takes longer to cook in the m...

Q 02/05

Which of these, like the kelvin, is one of the seven SI base units?

A) Litre

B) Newton

C) Kilogram

D) Coulomb

Answer · why

C) Kilogram

The kilogram. For more than a century it was defined by a platinum-iridium cylinder kept in a vault near Paris; since 2019 it has been fixed by a cons...

Q 03/05

Which everyday point is 273.15 on the Kelvin scale?

A) Water's boiling point

B) Body temperature

C) Room temperature

D) Water's freezing point

Answer · why

D) Water's freezing point

Water's freezing point, 0 °C. A kelvin is the same size as a degree Celsius, so converting between the two only shifts the zero by 273.15, down to the...

Q 04/05

What was the Celsius scale generally called before it was renamed in 1948?

A) Réaumur

B) Centigrade

C) Octogesimal

D) Delisle

Answer · why

B) Centigrade

Centigrade, from the Latin for 'hundred', was dropped in 1948 partly because in French the same word named a hundredth of a grade, a unit of angle; th...

Q 05/05

As of 2025, which American valley holds the official record for Earth's highest air temperature?

A) Monument Valley

B) Death Valley

C) Coachella Valley

D) Imperial Valley

Answer · why

B) Death Valley

Death Valley. Furnace Creek hit 56.7 °C (134 °F) on 10 July 1913; the valley floor lies below sea level between steep mountain walls, so heated air si...