1.简单
What is gamma radiation?
- AA slow-moving electron
- BA stream of helium nuclei with a positive charge
- CA fast stream of protons from the nucleus
- DHigh-energy electromagnetic radiation with no mass or charge
2.简单
Which state of matter has neither a fixed shape nor a fixed volume?
- ACrystal
- BSolid
- CLiquid
- DGas
3.简单
Which method separates two liquids with different boiling points, such as alcohol and water?
- AFiltration
- BUsing a magnet
- CDistillation
- DSieving
4.中等
In a closed container, 10 g of substance A reacts completely with 5 g of substance B. What is the total mass of the products?
- A5 g
- B50 g
- C15 g
- D10 g
5.中等
Which is larger, a sodium atom (Na) or a sodium ion (Na⁺)?
- AThe sodium ion
- BThey are the same size
- CThe sodium atom
- DIt depends on the temperature
6.中等
氧气分子 O₂ 中是哪种键?
- A离子键
- B非极性共价双键
- C极性共价单键
- D金属键
7.困难
What is a triglyceride made of?
- AOne glycerol molecule joined to three fatty acids
- BThree glucose molecules joined together
- COne fatty acid joined to three glycerol molecules
- DThree amino acids joined by peptide bonds
8.困难
Frying an egg turns the clear egg white solid and white. What happens to the proteins?
- AThey are converted into fats
- BThey are burned to carbon dioxide and water
- CThey are hydrolysed, so the peptide bonds break into separate amino acids
- DThey are denatured: their shape changes, but the peptide bonds stay intact
答案
- 1. D · High-energy electromagnetic radiation with no mass or charge
- 2. D · Gas
- 3. C · Distillation
- 4. C · 15 g
- 5. C · The sodium atom
- 6. B · 非极性共价双键
- 7. A · One glycerol molecule joined to three fatty acids
- 8. D · They are denatured: their shape changes, but the peptide bonds stay intact
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