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Science Multiple Choice #3

Can you answer these multiple choice questions from the world of science?
Quiz by Quizmaster
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Last updated: August 30, 2021
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First submittedAugust 30, 2021
Times taken31,402
Average score66.7%
Rating4.37
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1. Which type of blood vessel carries blood from the heart out to the rest of the body?
Arteries
Veins
2. Would you weigh less on the equator than the North Pole?
This is due to centrifugal force from the spinning of the Earth. The difference is about 1%
Yes
No
3. Where is the asteroid belt?
Between Earth and the Moon
Between Mars and Jupiter
Beyond Neptune
Scattered evenly throughout the Solar System
4. What sex chromosomes do most human males have?
About 1 in 1000 boys are born with XYY chromosomes
XX
XY
YY
5. What was the Cambrian Explosion?
An increase in diverse species beginning about 541 million years ago
An event where a Belgian quantum scientist accidentally created a black hole
The growth in scientific knowledge starting around 1400 AD
6. What phylum are humans in?
Animalia
Carnivora
Chordata
Primates
7. Take a sheet of metal with holes in it. Heat the metal. What happens to the holes?
They get larger
They get smaller
They stay the same size
8. Which continent has the greatest number of marsupial species?
Africa
Asia
Australia
9. Which of these particles has the lowest mass?
Electron
Neutron
Proton
10. How many molecules are in a mole?
usually 3
273
About 6.02 x 1023
11. What does Hertz measure?
Amplitude of an electromagnetic wave
Number of cycles per second
Strength of a magnetic field
12. What type of galaxy is the Milky Way?
Elliptical
Irregular
Spiral
13. What is E. coli?
an Algae
a Bacterium
a Fungus
a Virus
14. In 1971, astronaut David Scott dropped a hammer and a feather on the surface of the moon. What happened?
Here's a video of this experiment
The hammer fell faster
The feather fell faster
Both objects fell at roughly the same speed
15. If a radioactive substance has a half-life of 1 year, how much of it will be left in 3 years?
1/2
1/4
1/8
None
36 Comments
+19
Level 86
Aug 31, 2021
I think you could be nitpicking about the metal question. It depends on the exact shape and size of plate and holes and they might even get smaller first and then bigger.
+11
Level 73
Aug 31, 2021
The trick is to instead imagine the punched out metal discs instead of the holes. When heated, do these discs get bigger or smaller? Bigger, of course. Therefore, the holes that the discs were punched out of must grow larger.

I'm sure there are contrived situations where somehow this doesn't happen, but that goes against the spirit of these quizzes imo.

+56
Level 74
Sep 2, 2021
I think that's backwards, actually. Sure, the round disks would get larger - because the metal expands. The holes are not made of metal, however. By my thinking, the metal surrounding the holes will expand, and having no where else to go (well, there is the z-direction I suppose), it should expand into the holes.
+1
Level 48
May 22, 2024
I was thinking that if you take a block of a metal with holes, and heat it closer to liquid, it will try to even out, making the holes smaller. As other users pointed out, this can get pretty circumstantial.
+1
Level 63
Nov 23, 2024
I think it depends on how the metal is heated. If the metal is heated at a single point, the heat will diffuse outwards and the metal will be deformed. If the metal is heated uniformly, then the distance between atoms will also increase uniformly, and so the holes will grow. You can imagine taking an image of the metal and scaling it up by a constant.
+1
Level ∞
May 18, 2025
Frustrating that this incorrect explanation got 5 times as many upvotes as the correct one above it.

Instead of learning, people would rather hear someone tell them "No, you're not wrong, you already know it all. You're so smart."

+11
Level 67
Sep 7, 2021
This is exactly what I thought!
+27
Level 71
Sep 17, 2021
Think of a metal rod. As you heat it, it gets longer as a proportion of it's length and thicker as a proportion of its thickness. If the rod is 100 times as long as it is thick, the increase in length is 100x more than the increase in thickness. Now bend that rod into a circular ring. The same thing should happen. With such a large increase in length and such a small increase in thickness, the inner diameter of the ring must increase. Make a mesh of these and the holes all get bigger. But what about a tiny hole in a large disk? Cut the disk and straighten it into a rod. Will the rod's thickness ever be more than it's length? It can't be, otherwise, it would never reach around to close on itself, therefore, the holes in any disk must get larger with material expansion. The same applies to octagons, squares, triangles, etc.
+4
Level 80
Sep 17, 2021
Great explanation.
+4
Level 88
Sep 2, 2021
I also think it depends on how high you heat the metal and for how long, @Moos1005.

Not being a scientist, I’m thinking in terms of my perforated steel pizza-cooking tray. As I cook pizza a maximum temperature of 250 ℃, I wouldn’t expect any change perceptible to the naked eye in the size of the holes. However, should the same tray be heated to a temperature approaching its melting point, I suspect a more marked increase in the size of the holes may occur.

+7
Level 80
Sep 14, 2021
The metal question is correct. Think of it like this: heated metal atoms need more space between them to account for their heat energy. Say 100 atoms ran around the outer perimeter of a small hole. As the metal heats up, the 100 atoms need to be farther apart from the next closest one. Going inwards would push them closer together. They must go outwards to get more space and therefore the hole expands.
+4
Level 63
Sep 17, 2021
I don't get this at all. Metal expands when it's heated, so surely as the metal gets bigger, the holes get smaller?
+3
Level 69
Sep 17, 2021
When metal pipe is heated up both the ID and OD grow in diameter. The metal expands all the way around the pipe more then the wall thickness grows. Hope this helps.
+1
Level 32
Apr 24, 2025
What's the 'ID' and 'OD'? I am also extremely confused. Let me get this straight- When heated, molecules (or was it atoms?) move faster, and are more energetic. It expands (like gas)? Shouldn't it push the holes smaller???
+4
Level 56
Sep 1, 2021
The mole question is kind of strange. A mole isn't an object, it's a unit of measurement. It would be like asking "how many molecules are in a dozen?" You get what the question is asking, but a dozen doesn't necessarily represent a dozen molecules, and neither does a mole; you'd be better off asking "how many molecules are in 1 dozen/mole of molecules.
+23
Level 80
Sep 1, 2021
Would you like a nitpicking award?
+8
Level 70
Sep 2, 2021
'jonh' wins the Golden Nitpick Award for September 2021. Congratulations. ('CardinalSin' wins the 'Head Stirrers' wooden spoon award)
+21
Level 80
Sep 7, 2021
Wow. Giving out the award on the second of the month just shows how arbitrary your rewards are. Does anyone vet these proceedings? Do you have any system for actually awarding these prizes? You probably have big corporations influencing your decisions... you know, "Big Nitpick" keeping their most profitable nitpickers adulated. Stop being an industry sycophant and get back to the artistry of the nitpick. I remember when the Malbaby Nitpick Award meant something... before you sold out.
+2
Level 71
Sep 17, 2021
If I may claim the nitpicking award, a mole isn't even a unit of measurement. It is just a number, like a dozen or a million.
+3
Level 71
Sep 7, 2021
Brilliant quiz. Just tough enough to test general all around scientific literacy.
+4
Level 78
Sep 17, 2021
Centrifugal force does not exist. It's your angular momentum that would at some point exceed what the *centripetal* force (gravity) has to be in order to keep you at that orbital radius.
+2
Level 77
Sep 17, 2021
Whether centrifugal forces 'exist', depends on your frame of reference. The question is fine as it is.
+2
Level 28
Sep 22, 2021
It is an apparent force, and exists as such and can be used in calculations. In the reference frame of a car, you feel apparent wind. I can use that wind in drag calculations even though I know it's an apparent wind and the air isn't moving.
+4
Level ∞
Sep 17, 2021
We need Dr. Johnson to grab you, swing you around by your arms, and yell "I refute it thus", as he flings you into a wall.
+4
Level 71
Sep 17, 2021
https://xkcd.com/123/
+3
Level 59
Sep 17, 2021
Since nitpicking is big in this comment-section, I'll also intersect something:

Our galaxy is not just a spiral galaxy, in fact it is an barred spiral galaxy!

But since barred spiral galaxies are considered to be a sub-type of spiral galaxies, I'll let that pass for now...

+4
Level 54
Sep 17, 2021
Even though Australia is massive and a continental landmass, it is NOT considered a continent per se. It´s in Oceania.
+8
Level 79
Sep 17, 2021
Depends on who you talk to. There's no set scientific definition of what a "continent" is, so different places define it differently. Some consider North and South America to be a single continent, some consider it two. Same with Europe and Asia. Some consider Australia to be a continent, some consider it an island, some consider it both. Some say Oceania is the continent, others say it's just a region that contains the continent of Australia.
+1
Level 32
Apr 24, 2025
The Oxford dictionary (definition of continent) states: One of the seven major land areas on the Earth, which are North America, South America, Europe, Africa, Asia, Australia, and Antarctica.

But what about New Zealand and other island countries? It never said all the countries would be in the 'continents', but the Maldives are considered in Asia, as is Madagascar is considered in Africa.

+1
Level 55
May 30, 2025
But again, it's not necessary that the whole world needs to follow the Oxford Dictionary and go by its definition. They literally said, "different places define it differently."
+4
Level 69
Sep 17, 2021
The sheet of metal question could be worded better. There are a few exceptions that the holes would get smaller due to negative thermal expansion. The holes in a sheet of pure silicon heated from 20 K to 100 K (yes very cold) would get smaller.

"Take a sheet of metal with holes in it. Heat the metal from 0*C to 500*C. What happens to the holes?"

+3
Level 71
Sep 17, 2021
Silicon is not a metal, though. However, you have a great point. Invar is a metal alloy and it has a NTE from 200-340K.
+3
Level ∞
Sep 17, 2021
Okay, so 99.99999% of the time the holes getting bigger.
+1
Level 71
Sep 21, 2021
I think all BigLaing said was that there was room for improvement with the wording of the question. I agree, but I'm also sure you have higher priorities running the site.
+2
Level 74
Nov 5, 2023
wth with Australia suddenly being a continent? In a quiz by Quizmaster? (and I use the word "suddenly" wrongly)

I also wonder why you'd put the option "amplitude" if you're not going to put the correct option "frequency" in that question - it's right, but a bit weird.

What is 2?

A. an odd number

B. a number that when you halve it leaves a whole number with no decimal places

+2
Level 71
Jan 15, 2024
I'm shocked by the dishonesty of many popular music bands. Eagles are humans, not eagles; there isn't a single beetle in the Beatles. But the Chordettes live up to their name: they really are chordates.