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

Charles's law describes the relationship between which two properties of a gas, at constant pressure?

1. ADensity and mass
2. BPressure and volume
3. CPressure and number of moles
4. DVolume and temperature

Яка група містить благородні гази, як-от гелій і неон?

1. AГрупа 2
2. BГрупа 18
3. CГрупа 1
4. DГрупа 17

Which element exists naturally as diatomic molecules (two atoms joined together)?

1. AOxygen
2. BHelium
3. CIron
4. DSodium

An exothermic reaction is at equilibrium. What happens if the temperature is raised?

1. AThe equilibrium shifts toward the reactants
2. BThe equilibrium does not change
3. CThe reaction becomes endothermic
4. DThe equilibrium shifts toward the products, raising the yield

What is the oxidation number of sulfur in H₂SO₄?

1. A+2
2. B+6
3. C−2
4. D+4

Which element has chemical properties most similar to calcium?

1. AMagnesium
2. BCarbon
3. CScandium
4. DPotassium

Why are the radioactive tracers used for medical imaging usually chosen to have short half-lives?

1. AThey give a strong signal for imaging but leave the body's tissues exposed only briefly
2. BThey emit only alpha particles, which are harmless inside the body
3. CThey stay active for many years, so a single dose can be used for every future scan
4. DShort half-life isotopes are not radioactive

Which statement correctly distinguishes a scientific law from a scientific theory?

1. AA law describes what happens; a theory explains why it happens
2. BA theory becomes a law once it is proved
3. CA law is only a guess, while a theory is a proven fact
4. DLaws apply only to chemistry, theories only to biology