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

A cleaning solution has a pH of 12. How is it described?

1. ANeutral
2. BStrongly acidic
3. CWeakly acidic
4. DStrongly basic

What does the prefix "milli-" mean?

1. AOne-millionth (10⁻⁶)
2. BOne-thousandth (10⁻³)
3. COne thousand (10³)
4. DOne-hundredth (10⁻²)

What is an electrolyte?

1. AA substance that forms ions and conducts electricity when dissolved in water
2. BA metal that conducts electricity as a solid
3. CA substance that dissolves as whole molecules without forming any ions
4. DA gas that dissolves in blood

How does evaporation differ from boiling?

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

How many oxygen atoms are in one formula unit of calcium nitrate, Ca(NO₃)₂?

1. A5
2. B2
3. C3
4. D6

Which property stays the same whether you have a small sample or a large sample of a pure substance?

1. AMass
2. BDensity
3. CVolume
4. DTotal heat content

Each C=O bond in carbon dioxide is polar, yet the CO₂ molecule is nonpolar. Why?

1. ACarbon has lone pairs that cancel the dipoles
2. BCarbon and oxygen have the same electronegativity
3. CThe molecule is linear, so the two bond dipoles cancel out
4. DThe bonds are ionic, not covalent

Which approach best reduces a health worker's exposure to ionising radiation?

1. AStand closer to the source so the job is finished sooner and exposure is shorter
2. BLimit the time near the source, increase the distance and use shielding
3. CRely only on wearing gloves
4. DWork faster without any shielding