General Science (Physics, Chemistry, Biology Basics)
Core concepts
General science tests fundamental ideas rather than advanced mathematics. In physics, revise motion, force, energy, work, electricity, magnetism, light, sound, and heat. In chemistry, cover atomic structure, the periodic table, chemical bonding, acids and bases, pH, reactions, and separation techniques. In biology, study cell structure, mitosis and meiosis, genetics, human organ systems, nutrition, disease, and ecology. Questions often apply a concept to a everyday situation.
Traps
Common errors include confusing mass with weight, speed with velocity, and heat with temperature. In chemistry, candidates mix physical and chemical changes, misread pH direction, or forget that pH is logarithmic. In biology, mitosis and meiosis are frequently swapped, and correlation is mistaken for causation. Unit errors and reversed cause-effect statements are also common.
Worked example
A solution has pH 3, another pH 4. How much more acidic is the first? pH is logarithmic: each unit represents a tenfold change in hydrogen-ion concentration. pH 3 is 10 times more acidic than pH 4, not twice as acidic. This illustrates why pH differences must be compared multiplicatively.
Rule of thumb
Use dimensional analysis: write units at every step and cancel them. For definitions, state the quantity, its unit, and its direction or sign where relevant. When a graph is given, describe the trend before choosing a cause.