Робочий аркуш «Хімія для вступних іспитів на медсестринство» з відповідями

What is the smallest particle of an element that still has the chemical properties of that element?

1. AAn electron
2. BAn atom
3. CA proton
4. DA nucleus

What is radioactivity?

1. AThe flow of electrons through a metal wire
2. BThe glow produced by any hot object
3. CThe release of heat and light when fuels burn in air
4. DThe release of radiation by unstable atomic nuclei

What is the melting point of a substance?

1. AThe temperature at which it catches fire
2. BThe temperature at which its liquid turns into a gas
3. CThe temperature at which its solid turns into a liquid
4. DThe temperature at which it dissolves in water

How does evaporation differ from boiling?

1. AEvaporation produces a solid, while boiling produces a gas
2. BEvaporation happens only at the surface and at any temperature; boiling happens throughout the liquid at a set temperature
3. CEvaporation needs a higher temperature than boiling
4. DEvaporation happens throughout the liquid at a set temperature; boiling happens only at the surface

Which list is in order from smallest to largest mass?

1. AGram, milligram, kilogram
2. BMilligram, kilogram, gram
3. CMilligram, gram, kilogram
4. DKilogram, gram, milligram

Why does ice float on liquid water?

1. AIce contains trapped air from the freezer
2. BIce is denser than liquid water
3. CIce is less dense than liquid water
4. DIce has a higher mass than the same volume of water

Making ammonia (N₂ + 3H₂ ⇌ 2NH₃) is exothermic. A low temperature would give a higher yield, yet factories use a moderately high temperature. Why?

1. AAt low temperatures the reaction is too slow to be useful
2. BLow temperatures would make the ammonia explode
3. CHigher temperatures shift the equilibrium toward more ammonia
4. DThe catalyst only works when the reaction is endothermic

Orange bromine water is shaken with two hydrocarbons. With hexene it turns colourless; with hexane it stays orange. What does this show?

1. AHexene is an alcohol and hexane is an acid
2. BHexane contains a C=C double bond; hexene does not
3. CHexene contains a C=C double bond; hexane does not
4. DBoth contain double bonds, but hexane reacts more slowly