Miscellaneous
Refraction occurs because:
A light speeds up when it goes from air to glass or water.
B light slows down when it goes from air to glass or water.
C light stops when it goes from air to glass or water.
D light reflects inside transparent materials.
B light slows down when it goes from air to glass or water.
Which statement is true?
A Sound travels faster than light.
B Light does not travel. It is either on or off.
C Light travels faster than sound.
D Light and sound travel at the same speed.
C Light travels faster than sound.
In what way is ice different to other solid materials?
A It is colder.
B It occurs naturally.
C Ice (solid water) is less dense than liquid water.
D The density of ice does not change when it is cooled down.
C Ice (solid water) is less dense than liquid water.
Your image in a mirror:
A is always smaller than you
B is upside down.
C is always bigger than you.
D seems to be behind the mirror.
D seems to be behind the mirror.
How do we describe the way that energy is stored in batteries and food?
A kinetic energy
B chemical energy
C thermal energy
D potential energy
How do we describe the way that energy is stored in batteries and food?
A kinetic energy
B chemical energy
C thermal energy
D potential energy
A student burns two fuels: Fuel A produces a lot of soot, while Fuel B burns with a clean blue flame. What can you conclude?
A. Fuel A undergoes complete combustion
B. Fuel B undergoes incomplete combustion
C. Fuel A has less oxygen supply
D. Fuel B produces carbon monoxide
C. Fuel A has less oxygen supply
Why should water NOT be used on an oil fire?
A. Water reacts chemically with oil
B. Water increases the temperature
C. Water causes oil to spread and splash
D. Water removes oxygen
C. Water causes oil to spread and splash
A city introduces electric cars to reduce pollution. Which pollutant will decrease the MOST?
A. Carbon dioxide
B. Sulfur dioxide
C. Nitrogen oxides
D. Oxygen
C. Nitrogen oxides
Elements in the same group have similar properties because they have the same:
A. Number of protons
B. Number of shells
C. Atomic mass
D. Number of outer electrons
D. Number of outer electrons
A metal reacts slowly with acid and produces few bubbles. What can you infer?
A. It is highly reactive
B. It is below hydrogen in reactivity series
C. It is moderately reactive
D. It does not form a salt
C. It is moderately reactive
A bacterium reproduces by binary fission, while a yeast cell reproduces by budding.
Explain one similarity between these two types of asexual reproduction.
Similarity: Both binary fission and budding are forms of asexual reproduction and involve only one parent, producing genetically identical offspring (clones).
A bacterium reproduces by binary fission, while a yeast cell reproduces by budding.
Explain one difference between these two types of asexual reproduction.
Difference: In binary fission, the parent cell splits into two equal-sized cells, whereas in budding, a smaller daughter cell grows out of the parent and may remain attached for a short time.
A population of insects reproduces only by asexual reproduction for many generations.
Explain why this could be a problem if the environment changes suddenly.
Asexual reproduction produces no genetic variation, so all insects are very similar.
If the environment changes (for example, a new disease or climate change), none of the insects may have a trait that helps them survive, which could cause the population to decline or become extinct.
Explain two ways in which the structure of the alveoli makes gas exchange more efficient in the lungs.
During exercise, muscles respire faster.
Explain how the breathing system responds to meet the increased demand for oxygen.
The angle of incidence is 35°.
Calculate the angle of reflection.
According to the law of reflection:
Angle of incidence = Angle of reflection
So,
Angle of reflection = 35°
A light ray hits a mirror. The angle between the incident ray and the reflected ray is 80°.
Calculate the angle of incidence.
The incident ray and reflected ray are symmetrical about the normal.
So:
80° ÷ 2 = 40°
✅ Angle of incidence = 40°
A culture starts with 5 bacteria.
Each bacterium divides once every 30 minutes.
How many bacteria are present after 2 hours?
2 hours = 120 minutes
120 ÷ 30 = 4 divisions
Each division doubles:
5 × 16 = 80
✅ Final answer: 80 bacteria
The surface area of the small intestine without villi is 0.5 m².
Villi increase the surface area by 20 times.
Calculate the new surface area.
0.5 × 20 = 10 m²
Final answer: 10 m²
A section of intestine has 1,000 villi.
Each villus increases surface area by 0.02 mm².
Calculate the total increase in surface area.
1,000 × 0.02 = 20 mm²
Final answer: 20 mm²
A farmer plants seeds in cold, dry soil with little oxygen.
Explain why these conditions would slow down or prevent germination, even though the seed is alive.
Seeds need water to activate enzymes, oxygen for respiration, and a suitable temperature for enzymes to work efficiently. Cold, dry soil slows enzyme activity and limits respiration, so the seed does not have enough energy to grow and germination may not occur.
Explain how burning the fuel leads to air pollution and global warming, and describe one way a driver could reduce their carbon footprint while also improving fire safety.
Burning petrol is a type of oxidation that releases carbon dioxide and other pollutants into the air. These gases cause air pollution, which can harm human health, and carbon dioxide is a greenhouse gas that contributes to global warming by trapping heat in the atmosphere. A driver can reduce their carbon footprint by driving less or using public transport, which lowers the amount of fuel burned. Proper maintenance of the car also improves fire safety by reducing the risk of fuel leaks or overheating.
A school science lab tests the air near a busy road and finds high levels of carbon dioxide and nitrogen dioxide.
Explain how these gases form, why they are harmful to both health and the environment, and suggest one action that could reduce these results.
Carbon dioxide and nitrogen dioxide are formed during the burning (oxidation) of fuels in vehicle engines. Carbon dioxide is a greenhouse gas that contributes to global warming, while nitrogen dioxide causes air pollution that can irritate the lungs and worsen breathing problems. One way to reduce these results is to use public transport or low‑emission vehicles, which lowers fuel use and reduces the carbon footprint and pollution levels.
A metal spoon and a wooden spoon are left in a cup of hot water for two minutes.
Explain why the metal spoon becomes hot more quickly than the wooden spoon, referring to energy transfer.
The metal spoon becomes hot more quickly because metal is a better conductor of thermal energy than wood. Thermal energy is transferred through the metal by conduction, passing easily between particles. Wood is a poor conductor (an insulator), so energy is transferred more slowly, causing a smaller temperature change.
A house has brick walls but no insulation. In winter, the house cools down quickly.
Explain how insulation reduces energy transfer and helps keep the house warm.
Insulation reduces energy transfer by trapping air, which is a poor conductor of heat. This slows down conduction through the walls and reduces convection currents. As a result, less thermal energy escapes from the house, helping it stay warm for longer.