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

Which two substances must be present for iron to rust?

1. ANitrogen and water
2. BHydrogen and oxygen gas only
3. CCarbon dioxide and salt
4. DOxygen and water

What is gamma radiation?

1. AHigh-energy electromagnetic radiation with no mass or charge
2. BA stream of helium nuclei with a positive charge
3. CA fast stream of protons from the nucleus
4. DA slow-moving electron

Какое свойство типично для металлов?

1. AБольшинство из них — газы при комнатной температуре
2. BОни плохо проводят тепло
3. CОни хорошо проводят электрический ток
4. DЭто хрупкие твёрдые вещества, которые разбиваются

Water can act as an acid in some reactions and as a base in others. What is such a substance called?

1. AAmphoteric
2. BSaturated
3. CIsotonic
4. DNeutral

What is carbon-14 dating used for?

1. AFinding the exact age of rocks that are billions of years old
2. BEstimating the age of material that was once alive
3. CMeasuring body temperature
4. DDetecting carbon monoxide in a room

Сколько молей содержится в 88 г углекислого газа (молярная масса 44 г/моль)?

1. A2 моль
2. B44 моль
3. C3872 моль
4. D0,5 моль

Hyperbaric oxygen therapy places a patient in a chamber with oxygen at higher than normal pressure. Why does this raise the oxygen dissolved in blood plasma?

1. AHigher pressure turns the oxygen into a liquid
2. BGas solubility in a liquid increases with the partial pressure of the gas
3. CHigher pressure makes red blood cells divide faster
4. DHigher pressure lowers body temperature, so the blood can hold much more gas

Cotton soaked in ammonia (NH₃) and cotton soaked in hydrogen chloride (HCl) are placed at opposite ends of a glass tube. A white ring of ammonium chloride forms closer to the HCl end. What does this show?

1. ABoth gases diffuse at the same speed
2. BThe HCl molecules diffuse faster than NH₃ molecules
3. CThe lighter NH₃ molecules diffuse faster than HCl molecules
4. DThe white ring forms where the gases are heaviest