ใบงาน เคมีสำหรับข้อสอบเข้าพยาบาล พร้อมเฉลย

According to collision theory, what must happen for particles to react?

1. AThey must stay completely still next to each other
2. BThey must collide with enough energy and the right orientation
3. CThey must have the same mass
4. DThey must both be in the solid state at the same time

What is a precipitate?

1. AA gas that bubbles out when two solutions are mixed
2. BAn insoluble solid that forms when two solutions react
3. CA liquid that forms when a solid melts
4. DA substance that speeds up a reaction

What colour does blue litmus paper turn in an acid?

1. AGreen
2. BPurple
3. CRed
4. DBlue (no change)

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

1. AVolume
2. BTotal heat content
3. CDensity
4. DMass

When the diaphragm contracts and the chest cavity gets bigger, what happens to the air pressure inside the lungs?

1. AIt does not change
2. BIt falls, so air flows out
3. CIt rises, so air flows in
4. DIt falls, so air flows in

How does ionisation energy (the energy needed to remove an outer electron) generally change from left to right across a period?

1. AIt increases
2. BIt first falls, then rises sharply
3. CIt stays the same
4. DIt decreases

An isotope has a half-life of 8 days. How long does it take for 100 g to decay to 12.5 g?

1. A32 days
2. B24 days
3. C64 days
4. D16 days

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