Phiếu bài tập Hóa học cho kỳ thi đầu vào điều dưỡng có đáp án

About what percentage of dry air is oxygen?

1. A1%
2. B78%
3. C50%
4. D21%

What does the subscript 2 in H₂O tell you?

1. AEach molecule contains two oxygen atoms
2. BWater has a charge of 2
3. CEach molecule contains two hydrogen atoms
4. DThere are two water molecules

Between which kinds of elements do ionic bonds usually form?

1. ATwo identical metals
2. BTwo noble gases
3. CTwo nonmetals
4. DA metal and a nonmetal

How is 0,00045 written in scientific notation?

1. A4,5 × 10⁻⁵
2. B4,5 × 10⁻⁴
3. C4,5 × 10⁴
4. D4,5 × 10⁻³

Drops of water form on the outside of a glass of ice water. Where does this water come from?

1. AThe ice evaporates through the glass
2. BWater leaks through tiny holes in the glass
3. CThe glass releases water when it gets cold
4. DWater vapour in the air condenses on the cold glass

Rubbing alcohol evaporates faster than water at room temperature. What does this suggest?

1. AIts intermolecular forces are stronger than water's
2. BIts molecules are heavier than water molecules
3. CIts intermolecular forces are weaker than water's
4. DIt has a higher boiling point than water

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

1. AWork faster without any shielding
2. BStand closer to the source so the job is finished sooner and exposure is shorter
3. CLimit the time near the source, increase the distance and use shielding
4. DRely only on wearing gloves

How does soap help remove grease from skin?

1. ASoap molecules are completely nonpolar, so they dissolve grease like a solvent
2. BEach soap molecule has a polar end that attracts water and a nonpolar end that attracts grease
3. CSoap reacts with grease to form water and carbon dioxide
4. DSoap makes the grease more dense so it sinks