A sealed syringe contains 120 cm3120\text{ cm}^3120 cm3 of air at atmospheric pressure. Atmospheric pressure is 1.0×105 Pa1.0 \times 10^5\text{ Pa}1.0×105 Pa. The piston is pushed slowly inwards until the air occupies a volume of 40 cm340\text{ cm}^340 cm3. The temperature of the air remains constant. Calculate the new pressure of the air in the syringe.
A microscope is used to observe tiny pollen grains suspended in water.
Describe the motion of the suspended pollen grains (known as Brownian motion).
Explain what causes this motion of the pollen grains, in terms of the water molecules.
Describe how a diagram representing the molecular structure of a liquid should look. State how the arrangement and spacing of the molecules in a liquid differ from those in a solid.
321 exam-style questions on CIE IGCSE Physics 2.1 Kinetic particle model of matter, covering 2.1.1 States of matter and changes of state, 2.1.2a Particle structure and motion in solids, liquids and gases, 2.1.2b Gas pressure and particle collisions, 2.1.2c Brownian motion, 2.1.3a The absolute scale of temperature, and 2.1.3b Pressure, volume and temperature of a gas. Each one has a worked solution and a mark scheme showing where the marks go.