Natural Sciences (Physics, Chemistry, Biology)
Core concepts
This section spans physics, chemistry, and biology. In physics, apply Newton's laws, the work-energy relationship, Ohm's law, and wave properties; keep units consistent. In chemistry, understand atomic structure, the periodic table, chemical bonding, balancing equations, and acid-base reactions. In biology, know cell structure, genetics (dominant and recessive traits, Punnett squares), ecosystems, and human body systems.
Traps
- Forgetting to convert units (km to m, minutes to seconds) before calculating.
- Unbalanced chemical equations leading to wrong mole ratios.
- Confusing mass number with atomic number.
- Mixing dominant and recessive inheritance outcomes.
- Ignoring the difference between speed and velocity, or mass and weight.
Rule of thumb
In physics problems, list known values with units, state the formula, then substitute. In chemistry, always balance the equation before doing any mole calculation.
Worked example
A car travels 120 km in 2 hours. Speed = distance/time = 120 km / 2 h = 60 km/h. If the question asks for m/s, convert: 60 km/h = 60 × 1000 / 3600 ≈ 16.7 m/s.