1.简单
哪种元素的符号是 K?
- A氪
- B碳
- C钾
- D钙
2.简单
Between which kinds of elements do ionic bonds usually form?
- ATwo identical metals
- BTwo noble gases
- CTwo nonmetals
- DA metal and a nonmetal
3.简单
What is a beta particle?
- AA helium nucleus with two protons and two neutrons
- BA neutron that leaves the nucleus
- CA wave of visible light
- DA high-energy electron released from a nucleus
4.中等
Uranium-235 and uranium-238 both have 92 protons. How many more neutrons does an atom of uranium-238 have?
- A0
- B92
- C3
- D146
5.中等
In the reaction Zn + Cu²⁺ → Zn²⁺ + Cu, which species loses electrons?
- AZn²⁺
- BCu²⁺
- CCu
- DZn
6.中等
What is the molar mass of sulfuric acid, H₂SO₄ (H = 1, S = 32, O = 16 g/mol)?
- A50 g/mol
- B49 g/mol
- C96 g/mol
- D98 g/mol
7.困难
为什么油不溶于水?
- A油分子是带电的离子
- B油是非极性的,水是极性的,"相似相溶"
- C水太稠密,不能与任何东西混合
- D油与水反应生成固体
8.困难
Why is incomplete combustion of fuel in a poorly ventilated room dangerous?
- AIt produces water vapour, which is toxic
- BIt produces nitrogen, which replaces oxygen in the blood
- CIt produces extra oxygen, which damages the lining of the lungs over time
- DIt produces carbon monoxide, which binds to haemoglobin and blocks oxygen transport
答案
- 1. C · 钾
- 2. D · A metal and a nonmetal
- 3. D · A high-energy electron released from a nucleus
- 4. C · 3
- 5. D · Zn
- 6. D · 98 g/mol
- 7. B · 油是非极性的,水是极性的,"相似相溶"
- 8. D · It produces carbon monoxide, which binds to haemoglobin and blocks oxygen transport
完整分步解答:请在 examproblems.com 上练习本主题。