Why ice floats
Ordinary ice is less dense than liquid water. Freezing arranges water molecules into a structure with more space betw…
Facts
16 available pieces
Water entering the air
Evaporation changes liquid water into water vapour. Water can evaporate from a lake without reaching its boiling point.
One connected ocean
The ocean covers about 71 percent of Earth’s surface. Its named regions are connected parts of one global ocean.
Consonants that join in Devanagari
In Devanagari, a virama can suppress a consonant's inherent vowel and help form a conjunct with the next consonant. T…
Why the ocean looks blue
Water absorbs red light more strongly than blue light. Suspended particles can change the colours we see in the ocean.
Saturn’s average density
Saturn has a lower average density than water. This compares the planet as a whole, not every layer inside it.
Choosing Japanese conversion candidates
A Japanese input method can turn typed sounds into kana and offer kanji candidates for the same reading. The text is …
A slow turn on Venus
Venus takes about 243 Earth days to rotate once. Its orbit around the Sun takes about 225 Earth days.
How Hangul forms a syllable
A modern Hangul syllable block combines an initial consonant and a vowel, with a final consonant when needed. The let…
The Moon turns too
The Moon rotates as it travels around Earth. These movements take the same time, so we see nearly the same face.
The colour of Mars
Iron minerals help give Martian soil its reddish colour. Different surface materials also create variations in shade.
Drops on a cold glass
Condensation changes water vapour into liquid. On a humid day, droplets can form on the outside of a cold glass.
Spanish questions open and close
In Spanish, a written question or exclamation uses an opening mark as well as a closing mark: ¿…? or ¡…! The opening …
One visible character, several code points
A character that looks like one letter can contain more than one Unicode code point, such as a base letter followed b…
Why seasons change
Earth’s tilted axis changes how sunlight reaches each hemisphere during its orbit. This tilt produces our yearly cycl…
Why Chinese input shows candidates
When a Chinese input code is typed, a candidate window can show several characters that match it. Choosing the intend…