1.简单
What is the term for anything that has mass and takes up space?
- AHeat
- BForce
- CEnergy
- DMatter
2.简单
What colour does blue litmus paper turn in an acid?
- ARed
- BPurple
- CGreen
- DBlue (no change)
3.简单
What is the change from a liquid to a solid called?
- AFreezing
- BCondensation
- CEvaporation
- DMelting
4.中等
What is the molar mass of sulfuric acid, H₂SO₄ (H = 1, S = 32, O = 16 g/mol)?
- A49 g/mol
- B98 g/mol
- C96 g/mol
- D50 g/mol
5.中等
How does an antacid tablet relieve heartburn caused by excess stomach acid?
- AAn acid in it lowers the stomach pH further
- BA weak base in it neutralises some of the acid
- CIt turns the acid into a gas that is absorbed
- DIt coats the stomach and stops all acid production
6.中等
A room is at 25 °C. What is this temperature in kelvin?
- A77 K
- B−248 K
- C248 K
- D298 K
7.困难
Why does a sodium ion (Na⁺) have almost the same mass as a sodium atom?
- AThe ion has one fewer proton, which has a tiny mass
- BIons and atoms always have exactly the same mass
- CThe ion gains a neutron that balances the loss
- DThe only difference is one electron, which has a tiny mass
8.困难
Ethene has the structure H₂C=CH₂. How many electrons are shared between the two carbon atoms?
- A2
- B4
- C8
- D6
答案
- 1. D · Matter
- 2. A · Red
- 3. A · Freezing
- 4. B · 98 g/mol
- 5. B · A weak base in it neutralises some of the acid
- 6. D · 298 K
- 7. D · The only difference is one electron, which has a tiny mass
- 8. B · 4
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