Daily Practice · GCSE Science
September 1991 5-a-day
Every sheet in September 1991
The same date always regenerates the same five questions, so a sheet you print today is the sheet a classmate prints tomorrow.
- 1st September 1991A box has a driving force of 250 N forward and friction of 180 N backward. Calculate the resultant force, including its direction.
- 2nd September 1991Sound waves travel through a steel rail at approximately 5900 m/s. A sound wave sent along the rail has a frequency of 2950 Hz. Calculate its wavelength.
- 3rd September 1991State the eventual fate of a star with a much greater mass than the Sun, after it explodes as a supernova.
- 4th September 1991State the function of the mitochondria.
- 5th September 1991Which component of blood transports carbon dioxide, urea and hormones?
- 6th September 1991Explain why anaerobic respiration releases much less energy per glucose molecule than aerobic respiration.
- 7th September 1991Name the gland often called the body's master gland.
- 8th September 1991A student places ten 1 m x 1 m quadrats at random across a school field of area 3000 m2 and counts a total of 45 dandelions across all ten quadrats. Estimate the total number of dandelions on the field.
- 9th September 1991State what is meant by sustainable development.
- 10th September 1991Why can metals conduct electricity when solid?
- 11th September 1991State the pH value of a neutral solution.
- 12th September 1991State whether forming a new chemical bond requires energy or releases energy.
- 13th September 1991State the number of covalent bonds a carbon atom forms in a saturated hydrocarbon.
- 14th September 1991Explain, in terms of infrared radiation, how greenhouse gases keep the Earth warm.
- 15th September 1991A motor is supplied with 800 J of energy and wastes 240 J as heat. Calculate its efficiency as a percentage.
- 16th September 1991What is the difference between alternating and direct current?
- 17th September 1991What observation showed that the atom is mostly empty space?
- 18th September 1991State the equation that links pressure, force and area.
- 19th September 1991In a simple d.c. electric motor, state the name and function of the component that reverses the current in the coil every half turn.
- 20th September 1991In the microbiology practical, why are agar plates incubated at 25 degrees Celsius in schools rather than at 37 degrees Celsius?
- 21st September 1991An amylase reaction is complete after 200 seconds. Calculate the rate of reaction using rate = 1000 / time.
- 22nd September 1991Why can HIV not be treated with antibiotics?
- 23rd September 1991Name the gland that monitors and controls blood glucose concentration.
- 24th September 1991Explain why genetic engineering can introduce a new characteristic in a single generation, while selective breeding cannot.
- 25th September 1991An atom has atomic number 11 and mass number 23. State the number of protons.
- 26th September 1991State the trend in reactivity down group 7 and name the most reactive halogen listed on the periodic table.
- 27th September 1991Define the limiting reactant.
- 28th September 1991State whether the combustion of methane is exothermic or endothermic.
- 29th September 1991State the two named reactants used in the Haber process.
- 30th September 1991Explain how the sodium hydroxide test distinguishes aluminium ions from calcium ions, given that both give a white precipitate.