General Science
General Science tests basic physics, chemistry, biology, and health awareness at the school-science level. Numerical questions are usually simple but unit-sensitive.
Core rules
- Speed = distance/time; acceleration = change in velocity/time; force = mass × acceleration.
- pH below 7 is acidic, 7 is neutral, above 7 is basic. pH is negative log of hydrogen-ion concentration.
- Photosynthesis uses chlorophyll, sunlight, CO2, and water to produce glucose and oxygen.
- Vitamins: A for vision, C for collagen and immunity, D for calcium absorption, K for clotting.
- Blood groups depend on antigens; O negative is called the universal donor.
Worked example
Question: “A solution has [H+] = 1 × 10⁻⁴ M. What is its pH and nature?” Reasoning: pH = −log[H+] = −log(10⁻⁴) = 4. Since 4 < 7, the solution is acidic. Answer: pH 4, acidic.
Traps
- Using pH 7 as acidic instead of neutral.
- Mixing universal donor (O negative) with universal recipient (AB positive).
- Forgetting that acceleration involves direction as well as magnitude.
- Confusing vitamins with minerals.