50 free Heat trivia questions with answers — science & nature quiz, new questions added Aug 2026.
This heat trivia quiz covers the physics of heat and temperature the way a classroom does, with the stories attached. It starts with the basics: the three ways heat moves, the joule and the calorie, the specific heat of water, and what latent heat means. Then it walks the temperature scales and the people behind them: Daniel Gabriel Fahrenheit's brine and mercury, Anders Celsius's upside-down scale and the botanist who flipped it, William Thomson becoming Lord Kelvin, and the hunt for absolute zero from Amontons to the 2019 SI redefinition. It closes with heat in the world: Death Valley's record, lightning at 30,000 °C, the Sun's 15-million-kelvin core, Finnish saunas, water boiling at 71 °C on Everest, and the melted candy bar that gave us the microwave oven. The easy questions ask which unit measures heat, what absolute zero is in Celsius, and which metal filled early thermometers. The harder ones ask who coined 'latent heat' for whisky distillers, which count bored cannon in Munich to refute caloric theory, which year the 'degree Kelvin' lost its degree, and what the first microwave oven was called. Our thermodynamics quiz and physics quiz are the neighbouring pages. Every answer was checked against the encyclopaedia entry for the concept, scale or scientist before publishing, and the sentence that supports it is stored with each question.
30 of 50 questions with answers and explanations. Play the quiz
Q 01What is the SI unit of measurement for heat?
Joule
Heat is a process quantity: a system does not 'contain' it, it transfers it.
Q 02The SI unit of energy is named after which English physicist, a brewer's son?
James Prescott Joule
He lived from 1818 to 1889 and was the son of a wealthy Salford brewer.
Q 03How many joules is one thermochemical calorie now defined to equal?
4.184
The 'large' calorie on food labels is a kilocalorie, 4,184 J.
Q 04Who first introduced the calorie as a unit of heat energy, in lectures in 1819–1824?
Nicolas Clément
The lectures were on experimental calorimetry.
Q 05How many joules raise the temperature of 1 kg of water by 1 K?
4,184
Water has one of the highest specific heat capacities of any common substance.
Q 06Which heat-transfer mechanism works by warmer, less dense fluid rising and cooler fluid sinking?
Convection
It applies to liquids and gases alike, from a saucepan to the atmosphere.
Q 07Which mechanism is the diffusion of heat within a material or between materials in contact?
Conduction
In metals it is dominated by free electrons; in diamond, by lattice vibrations.
Q 08Above roughly what temperature does thermal radiation become visible as a glow?
525 °C
That visible glow is called incandescence; at room temperature emission is mostly infrared.
Q 09Which allotropes of carbon are credited with the highest thermal conductivities at room temperature?
Graphite and diamond
Diamond conducts heat via lattice vibrations rather than free electrons.
Q 10Who introduced the term 'latent heat' around 1750, commissioned by Scotch whisky producers?
Joseph Black
The distillers wanted the ideal quantities of fuel and water for their stills.
Q 11What is absolute zero on the Celsius scale?
−273.15 °C
It equals 0 K and −459.67 °F.
Q 12Which French physicist first asked in 1703 whether there is a limit to coldness?
Guillaume Amontons
The question arose from his improvements to the air thermometer.
Q 13Which scales set their zero points at absolute zero by definition?
Kelvin and Rankine
Rankine uses Fahrenheit-sized degrees; Kelvin uses Celsius-sized ones.
Q 14In which year did William Thomson publish 'On an Absolute Thermometric Scale'?
Q 21How many Fahrenheit degrees separate water's freezing and boiling points?
180
Freezing was defined as 32 °F and boiling as 212 °F at standard pressure.
Q 22Fahrenheit's upper fixed point, average human body temperature, was finally set at what?
96 °F
He had originally set it at 90 °F.
Q 23In 1714 Daniel Gabriel Fahrenheit built a reliable thermometer using which liquid?
Mercury
Earlier devices had used alcohol and water mixtures.
Q 24Galileo and Santorio Santorio built early temperature devices with an air-filled what?
1848
He was later ennobled as Lord Kelvin.
Q 15When the kelvin joined the SI in 1954, 273.16 K was defined as the temperature of what?
Triple point of water
The 2019 SI revision instead fixed the Boltzmann constant.
Q 16In which year was 'degree Kelvin' (°K) renamed simply 'kelvin' (K)?
1968
Resolution 3 of the 13th CGPM made the change.
Q 17Anders Celsius's original 1742 scale set which value at the boiling point of water?
0
His scale ran upside-down, with 100 at freezing; it was reversed after his death.
Q 18Which Swedish botanist reversed Celsius's scale in 1744 to the form used today?
Carl Linnaeus
The change coincided with Anders Celsius's death.
Q 19What was the profession of Anders Celsius, after whom the scale is named?
Astronomer
The scale was long called centigrade, from the Latin for 100 steps.
Q 20Fahrenheit's 0 °F was set as the freezing point of a brine of water, ice and which salt?
Ammonium chloride
A German story says he chose the coldest winter air temperature in Danzig in 1708–09 and only later reproduced it with brine.
Glass bulb
The bulb connected to a tube partially filled with water.
Q 25A bimetallic-strip thermometer bends because of differing what between two metals?
Thermal expansion
The same principle once switched older home thermostats on and off.
Q 26James Joule's father ran what kind of business in Salford?
A brewery
Joule later managed it and around 1840 began investigating replacing its steam engines with electric motors.
Q 27Who observed heat from boring cannon in Munich and reported on it in 1798?
Count Rumford
Born Benjamin Thompson, he immersed a cannon barrel in water with a blunted boring tool to make it boil.
Q 28Which chemist introduced a version of the caloric theory, treating heat as a fluid?
Antoine Lavoisier
Rumford's cannon experiments were an early blow against it.
Q 29Benjamin Thompson, the cannon-boring count, also laid out which Munich park in 1789?
Englischer Garten
It remains one of the largest urban public parks in the world.
Q 30Who invented the vacuum flask, or thermos, in 1892?
James Dewar
It is two flasks, one inside the other, joined at the neck with a vacuum between them.