Science Quiz

Answer: Cm. Curium, symbol Cm, is the chemical element with atomic number 96.

Answer: CO2. We exhale carbon dioxide.

Answer: One calorie. One calorie is the energy needed to raise 1g of water by 1°C.

Answer: Pascal. Pressure is measured in Pascals.

Answer: Hydrogen. Hydrogen is the lightest.

Answer: Gravity. Gravity keeps us on the ground.

Answer: How acidic or basic a solution is. The scale runs from 0 to 14: 7 is neutral, like pure water. Lemon juice is around 2, soap around 10. So vinegar and descaler play on the same team.

Answer: The water was supercooled: liquid below 0 °C, with nothing to start the crystals. Very pure, undisturbed water can stay liquid down to about −40 °C in ideal conditions. A knock or a speck of dust is enough for a first crystal to form, and ice spreads through the bottle within seconds. Supercooled droplets in clouds are feared in aviation, because they freeze instantly on the wings.

Answer: The pitch drop experiment, which has released only about ten drops in nearly a century. At the University of Queensland, pitch set in a funnel flows so slowly that a drop falls roughly every ten years. Its viscosity is hundreds of billions of times that of water. For decades nobody saw a drop fall live: a camera failed at the crucial moment.

Answer: Their phosphorescent material stores light energy and releases it slowly. Unlike fluorescence, phosphorescence continues after the light is switched off, sometimes for hours. Luminous watch hands once contained dangerous radium; today harmless pigments such as strontium aluminate are used.

Answer: 1901 discovery of X-rays. The German physicist Wilhelm Conrad Röntgen received the very first Nobel Prize in Physics in 1901 for his discovery of X-rays (1895).

Answer: Folic acid. Vitamin B9 is folic acid.

Answer: DNA double helix. They described the double helix of DNA.

Answer: Dispersion. Dispersion separates the colours.

Answer: 1,480 m/s. Sound travels at 1,480 m/s in water.

Answer: About 70 °C. Air pressure there is about three times lower than at sea level, so water boils sooner. Result: you cannot cook pasta properly, because the water never gets hot enough.

Answer: Decaffeinating coffee. Beyond its critical point (31 °C and 74 bar), CO₂ dissolves caffeine like a liquid while seeping into the beans like a gas. Then you simply lower the pressure: it turns back into gas and escapes, leaving no solvent residue.

Answer: The pressure pushes the grains apart (dilatancy): water seeps into the enlarged gaps and leaves the surface. Tightly packed grains have to move apart in order to shift: the volume of the gaps increases and draws water from the surface, which looks dry for a moment. The physicist Osborne Reynolds described this as early as 1885.

Answer: The ratio between the mass and the electric charge of its ions. Molecules are turned into ions, then deflected by electric or magnetic fields: their path depends on their mass and charge. The technique is used in anti-doping tests and pollution analysis… and was even carried by the Rosetta probe to analyse a comet.

Answer: Magnetostriction. Under the field, the material's magnetic domains line up and deform it by a few millionths. It causes the hum of transformers, whose plates vibrate in step with the alternating current. Some special alloys use it in sonar devices.