GenEd Science covers physics, chemistry, biology, earth science, and environmental science at a general-knowledge level. Expect questions on the Big Bang, the mole concept, classification of organisms, and applied topics like e-waste.
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Sample questions with answers and explanations
Sample 1
What is the process by which a solid substance changes directly into a gas without passing through the liquid state?
AEvaporation
BCondensation
CSublimation✓
DDeposition
Answer: C
Sublimation is when a solid changes directly into a gas without first becoming liquid. Dry ice (frozen carbon dioxide) is the classic example — it doesn't melt into a puddle; it turns straight into vapor. Mothballs do the same thing: they slowly shrink in your closet without leaving any wet residue. The reverse process — gas going directly to solid — is called deposition (frost on cold windows is one example).
Why the other choices are wrong
A. Evaporation is liquid → gas. Different transition.
B. Condensation is gas → liquid. Different transition.
D. Deposition is the reverse of sublimation: gas → solid (like frost forming directly from water vapor).
Sample 2
What is the primary cause of the seasonal changes experienced on Earth?
AThe distance between the Earth and the Sun varies throughout the year.
BThe Earth's axial tilt as it revolves around the Sun.✓
CThe speed of the Earth's rotation on its axis.
DThe influence of the Moon's gravitational pull on the tides.
Answer: B
Earth's axis is tilted about 23.5 degrees relative to its orbit around the Sun. As Earth orbits over the year, the same hemisphere alternately leans toward and away from the Sun. When the Northern Hemisphere leans toward the Sun (around June), it gets more direct sunlight and longer days — that's summer there. Six months later it leans away, gets oblique sunlight and shorter days — winter. Earth's distance from the Sun changes only slightly during the orbit and isn't what causes the seasons; the axial tilt is.
Why the other choices are wrong
A. Earth's distance from the Sun varies only slightly across the year and isn't the main driver of seasons.
C. Rotation speed determines day length but is roughly constant; it doesn't cause seasonal change.
D. The Moon's gravity drives tides, not seasons.
Sample 3
According to Newton's Third Law of Motion, if a swimmer pushes the water backward to move forward, what is the reaction force?
AThe water pushing the swimmer forward✓
BThe weight of the swimmer
CThe buoyancy of the water
DThe friction between the swimmer and the water
Answer: A
Newton's Third Law: for every action, there is an equal and opposite reaction. When a swimmer pushes water BACKWARD with their hands and feet, the water pushes the swimmer FORWARD with the same force. This is exactly how all locomotion in a fluid works — boats, fish, rockets all use the same principle. The reaction force from the water is what propels the swimmer; without it, you'd just paddle in place.
Why the other choices are wrong
B. Weight is gravity pulling the swimmer down, not the forward propulsion force.
C. Buoyancy is the upward force keeping the swimmer floating, not what moves them forward.
D. Friction with water DOES exist (drag), but it slows the swimmer rather than propelling them.
