Chemistry
What are the three common states of matter found on Earth?
Solid, liquid, gas
This term describes an animal that only eats plants.
What is the SI unit for force?
The newton (N).
Name three types of celestial objects other than planets.
Stars, moons, asteroids, comets, meteors, constellations, galaxies (any three).
This term refers to animals that are active at night rather than during the day.
Which process separates a soluble solid from a liquid by heating until the liquid evaporates, leaving crystals behind?
Crystallisation (via evaporation and cooling to form crystals)
What is the rank in the biological classification system that comes directly above species?
Genus
Name two forces that can cause a change in an object's motion.
Examples: friction, gravity, magnetic force, electrostatic force, applied push/pull.
Which planet in our solar system is known for its prominent rings?
Saturn
This scientist is known for the theory of relativity and the famous equation E = mc².
Albert Einstein
This piece of equipment is used to accurately measure the volume of liquids. It has markings along the side and is more precise than a beaker.
Measuring cylinder
Name two characteristics used to group organisms in a dichotomous key.
Examples: presence/absence of particular structures (wings, leaves), number of legs, type of mouthparts, habitat, etc.
What simple machine is a ramp, and how does it provide a mechanical advantage?
An inclined plane (ramp) reduces the force needed to lift an object by increasing the distance over which the force is applied — mechanical advantage = load/effort.
What causes the phases of the Moon as seen from Earth?
Phases result from the relative positions of the Sun, Earth, and Moon; we see different fractions of the Moon's lit side as it orbits Earth.
This planet has the strongest winds in the solar system, reaching over 1,600 km/h.
Neptune
Give two techniques you would use to separate a mixture that contains sand, salt, and water, and briefly state the step that removes each component.
Step 1: Use filtration to remove sand (insoluble solid). Step 2: Evaporate or distil water to recover salt (dissolved). Distillation can also separate saltwater into water and dissolved salts.
What is the main difference between a food chain and a food web?
A food chain shows a single linear path of energy transfer; a food web shows interconnected food chains and multiple feeding relationships.
Explain how friction affects the motion of a sliding object and give one way to reduce friction.
Friction opposes motion and converts kinetic energy to thermal energy; to reduce friction use lubrication, smoother surfaces, or wheels/bearings.
Explain why seasons occur on Earth (mention Earth's tilt and orbit).
Seasons occur because Earth's axis is tilted; during different parts of the year, either hemisphere tilts toward the Sun (more direct sunlight, summer) or away (less direct sunlight, winter).
This organ in the human body is responsible for filtering waste from the blood.
Kidney
Explain how chromatography can separate the different coloured pigments in a mixture (outline the basic principle).
Different pigments travel different distances
Explain how the removal of a top predator can affect a food web.
Removal of a top predator can lead to an increase in prey populations, which can overconsume lower trophic levels, causing cascading ecosystem changes (trophic cascade).
A box is pulled with two forces: 5 N5 N to the right and 3 N3 N to the left. What is the net force and direction? (Show calculation.)
Net force = 5 N−3 N=2 N to the right.
Describe how tides are influenced by both the Moon and the Sun.
The Moon's gravity pulls on Earth's oceans causing bulges (high tides); the Sun also exerts gravitational pull — when Sun and Moon align (spring tides), tides are higher; when at right angles (neap tides), tidal range is smaller.
This gas is needed for burning (combustion) to occur.
Oxygen