Химия для вступительных экзаменов на сестринские программы: лист заданий с ответами

Which technique is used to separate the different coloured dyes in an ink?

1. ADistillation of the ink
2. BMagnetism
3. CFiltration
4. DChromatography

According to collision theory, what must happen for particles to react?

1. AThey must both be in the solid state at the same time
2. BThey must stay completely still next to each other
3. CThey must have the same mass
4. DThey must collide with enough energy and the right orientation

Which of these is a polyatomic ion?

1. ASulfate, SO₄²⁻
2. BChloride, Cl⁻
3. CSodium, Na⁺
4. DOxide, O²⁻

Why does the vapour pressure of a liquid increase as it is heated?

1. AThe molecules become heavier and press harder on the surface
2. BMore molecules have enough energy to escape into the gas phase
3. CThe liquid's volume decreases and squeezes out vapour
4. DThe attractions between the molecules become stronger

Что происходит с температурой ледяной воды, пока лёд тает?

1. AОна падает ниже 0 °C
2. BОна непрерывно растёт всё это время
3. CОна сразу поднимается до 100 °C
4. DОна остаётся равной 0 °C, пока не растает весь лёд

What is the shape of a water molecule?

1. ABent
2. BTetrahedral
3. CFlat triangle
4. DLinear

Steel can be protected from rusting by coating it with zinc (galvanising). Why does the steel stay protected even if the zinc coating is scratched?

1. AZinc is less reactive than iron, so it pushes oxygen and water away from the iron
2. BZinc absorbs all the water from the air
3. CZinc is more reactive than iron, so it corrodes instead of the iron
4. DZinc turns the iron into a noble metal

J.J. Thomson's cathode ray experiments led to which discovery?

1. AAtoms have a dense, positively charged nucleus
2. BElectrons occupy fixed energy levels
3. CThe nucleus contains uncharged neutrons
4. DAtoms contain small, negatively charged particles