Daily Practice · GCSE Science
September 1999 - GCSE Science 5-a-day
Every GCSE Science sheet published in September 1999, with answers. Biology, chemistry and physics recall, definition and calculation, drawn from every strand.
Every sheet in September 1999
The same date always regenerates the same five questions, so a sheet you print today is the sheet a classmate prints tomorrow.
- 1st September 1999A cube-shaped model cell has sides of length 3 cm. Calculate the surface area to volume ratio of the cube. Give your answer in the form n : 1.
- 2nd September 1999Why does a food test for sugars need a water bath?
- 3rd September 1999Explain what is meant by a double blind trial.
- 4th September 1999Name the chemical released at a synapse that carries the signal across the gap.
- 5th September 1999Explain why deforestation to create land for cattle grazing can reduce biodiversity.
- 6th September 1999Name the four stages usually considered in a life cycle assessment of a product.
- 7th September 1999A student says that metals conduct electricity because they contain free-moving ions. Explain why this statement is incorrect, and give the correct explanation.
- 8th September 1999Give the formula for atom economy.
- 9th September 1999Explain, in terms of the reaction pathway, why adding a catalyst increases the rate of a reaction without changing the overall energy change of the reaction.
- 10th September 1999State two products, other than water, that can be formed during the incomplete combustion of a hydrocarbon.
- 11th September 1999State one advantage of running known reference substances alongside an unknown sample on the same chromatogram, rather than only comparing to published Rf values.
- 12th September 1999How is the uncertainty in a set of repeated readings usually estimated?
- 13th September 1999Define electric current.
- 14th September 1999A source has a half-life of 5 days and an initial activity of 1600 Bq. What is its activity after 15 days?
- 15th September 1999Explain why a larger vehicle mass increases braking distance.
- 16th September 1999State the type of force that always acts between an induced magnet and the magnet that induced it.
- 17th September 1999Name the model of the origin of the universe that is supported by red-shift observations.
- 18th September 1999Calculate the surface area to volume ratio of a cube of side 2 cm.
- 19th September 1999Which type of pathogen causes athlete's foot, a fungal skin infection?
- 20th September 1999Define oxygen debt.
- 21st September 1999Explain one benefit of the Human Genome Project.
- 22nd September 1999Give the resolution of a burette that can be read to the nearest half of a small division.
- 23rd September 1999Why is an atom electrically neutral?
- 24th September 1999State the law of conservation of mass.
- 25th September 1999Explain why solid sodium chloride does not conduct electricity, but molten sodium chloride does.
- 26th September 1999In the gas-volume required practical measuring how concentration affects rate, state one variable that should be controlled.
- 27th September 1999Give one piece of evidence that a solid sample is impure, based on its melting behaviour.
- 28th September 1999Explain why carbon monoxide is dangerous even though it has no smell.
- 29th September 1999Why can no device be 100 percent efficient?
- 30th September 1999Why is melting described as a physical change?