Observations and Diffusion

Order the diagrams to show Les’ observations. The circles represent particles of potassium manganate(VII).

The diagrams above show diffusion. State the meaning of the word diffusion. Use the word particles in your answer.

Potassium dichromate (VI) is very toxic if swallowed. It can also cause skin ulcers. Suggest how Pippa can reduce the risk from each of these hazards.

Pippa decides to repeat the investigation three times. She writes down the distance from the top of the agar to the bottom of the iodine colour in each investigation. - first time: 0.5 cm - second time: 0.6 cm - third time: 0.4 cm Calculate the mean average distance from these results. Show your working.

Describe, in terms of energy, the changes in movement of particles when a liquid changes to a gas.

Use the data in the table to work out the state of matter of each substance at 25 ºC.

Phil has samples of three metals – copper, manganese, and rubidium. Phil wants to know the density of the three metals. The density of a substance is the mass of 1 cm³ of the substance. He measures the mass and volume of his metal samples and writes his data in the table below. Calculate the density of each metal, and write it in the table above. Use the equation: mass (g) ÷ volume (cm³). Show your working below.

Use data from the table to suggest a reason for the difference in density between manganese and copper.

Calculate the total magnification, show your workings. The eyepiece lens has a magnification of 10 and the objective lens magnification is 20. Use the formula: total magnification = eyepiece magnification × objective lens magnification.

Amoebas are animals. Name two differences between animal and plant cells.