Easy
General Knowledge
Everyday Origins
Where ordinary words and objects actually came from.
Sample question
Start quiz
The English word "salary" comes from the Latin word for which substance?
Everyday Science You Half Know
These are the explanations everyone has heard, and most people could not quite reproduce.
About this topic
There is a set of everyday phenomena that everybody has had explained at some point and almost nobody could explain back. Why the sky is blue but sunsets are red. Why ice floats when nearly every other solid sinks in its own liquid. Why a cut onion makes you cry. The explanations are genuinely short, and knowing them makes ordinary surroundings slightly more legible. None of these questions requires any physics beyond what a curious person can hold in their head.
Questions & answers
Everyday Science You Half Know: all 10 questions and answers
Every question in this quiz is listed below with its correct answer and the reasoning behind it. Play first if you would rather not see the answers — or read through as a study sheet.
Play it insteadShow all answers and explanationsHide answers
-
1Why does the sky appear blue?
- A The oceans reflect upward
- B Air is naturally blue
- C Sunlight is blue before it arrives
- D Shorter blue wavelengths scatter more in the atmosphere Correct
Answer: D. Shorter blue wavelengths scatter more in the atmosphere
Why: The same scattering makes sunsets red: low sun means a longer path through air, and the blue has been scattered away before it reaches you.
-
2Why does ice float?
- A Ice is warmer than water
- B Surface tension holds it up
- C Water expands as it freezes, so ice is less dense Correct
- D Ice traps air bubbles
Answer: C. Water expands as it freezes, so ice is less dense
Why: Water is unusual in this. If ice sank, lakes would freeze from the bottom up and the consequences for life would be severe.
-
3Why does cutting an onion make you cry?
- A It releases fine dust
- B It releases a compound that irritates the eyes Correct
- C It gives off heat
- D Its acidity evaporates
Answer: B. It releases a compound that irritates the eyes
Why: Damaged cells release a sulphur compound that becomes an irritant on contact with the film of moisture on the eye.
-
4Why is the sea salty?
- A Rivers carry dissolved minerals from rock into it Correct
- B Sea creatures produce salt
- C It has always contained added salt
- D Rain is salty
Answer: A. Rivers carry dissolved minerals from rock into it
Why: Water evaporates and the salt stays behind, so concentration builds over geological time. Lakes with no outlet get salty for the same reason.
-
5Why do we see lightning before we hear thunder?
- A Thunder starts later
- B Sound is blocked by cloud
- C Lightning is closer
- D Light travels far faster than sound Correct
Answer: D. Light travels far faster than sound
Why: Sound covers roughly a kilometre every three seconds, so counting the gap gives a usable distance.
-
6Why does bread go stale?
- A Bacteria consume the sugar
- B The gluten dissolves
- C Starch molecules recrystallise, pushing out water Correct
- D It absorbs too much moisture
Answer: C. Starch molecules recrystallise, pushing out water
Why: It happens faster in the fridge than at room temperature, which is why bread should not be refrigerated.
-
7Why does a mirror appear to reverse left and right but not up and down?
- A It does reverse vertically too
- B It reverses front and back, which we interpret as left-right Correct
- C Gravity affects the reflection
- D The glass is curved slightly
Answer: B. It reverses front and back, which we interpret as left-right
Why: The mirror flips along the axis pointing at it. We read the result as a left-right swap because that is how we imagine turning around.
-
8Why do metal objects feel colder than wooden ones at the same temperature?
- A Metal conducts heat away from your skin faster Correct
- B Metal is genuinely colder
- C Wood generates heat
- D Metal reflects body heat
Answer: A. Metal conducts heat away from your skin faster
Why: You are sensing the rate of heat loss rather than temperature, which is why a thermometer disagrees with your hand.
-
9Why does the Moon appear to follow you when you travel?
- A It orbits alongside the car
- B Atmospheric refraction bends its image
- C Its light travels in a curve
- D It is far enough away that its direction barely changes Correct
Answer: D. It is far enough away that its direction barely changes
Why: Nearby objects sweep past as your angle to them changes rapidly. The Moon is distant enough that the angle stays effectively fixed.
-
10Why does hot water sometimes freeze faster than cold?
- A Heat destroys impurities
- B It never does
- C It is disputed, and the effect is not reliably reproduced Correct
- D Hot water is less dense
Answer: C. It is disputed, and the effect is not reliably reproduced
Why: The Mpemba effect has been reported many times and resists a settled explanation. Careful experiments often fail to reproduce it.
Frequently asked questions about Everyday Science You Half Know
How many questions are in Everyday Science You Half Know?
Everyday Science You Half Know has 10 questions and takes about 6 minutes to finish. It is rated Easy and sits in our General Knowledge category.
How is Everyday Science You Half Know scored?
Each of the 10 correct answers adds 10 XP, up to 100 XP for a clean run. Wrong answers cost you nothing, and your full question-by-question review is shown at the end.
Are the answers to Everyday Science You Half Know explained?
Yes. All 10 questions carry a written explanation of why the correct answer is right, so the quiz works as a study sheet as well as a test.
Can I replay Everyday Science You Half Know?
Yes, as often as you like. The questions and the answer options are reshuffled on each run, and you can use Practice Mistakes afterwards to retry only the ones you missed. No account is needed to play.
QuizKite Quality Guarantee
Every quiz on QuizKite is researched, written and fact-checked by hand against reliable references, with an explanation for each answer. Read our full Editorial Policy to learn more about our content standards.
Keep going
More General Knowledge
Medium
General Knowledge
Signs, Symbols and Standards
The everyday symbols and conventions nobody explicitly teaches you.
Sample question
Start quiz
The symbol & is called what?
Medium
General Knowledge
Collective Nouns and Curious Names
A murder of crows, a parliament of owls, and the proper names for ordinary things.
Sample question
Start quiz
A group of ravens is traditionally called what?
Medium
General Knowledge
Firsts, and Who Actually Got There
The first of various things, and the people who usually get the credit instead.
Sample question
Start quiz
The first successful vaccine was developed against which disease?
Medium
General Knowledge
How the World Agreed on a Metre
Where our units came from, and the arbitrary decisions still built into them.
Sample question
Start quiz
The metre was originally defined as a fraction of what?
Medium
Education & Learning
School Systems Around the World
Selection, apprenticeships, entrance exams and how differently countries organise schooling.
Sample question
Start quiz
The word kindergarten was coined in which country?