Physics and Chemistry Fundamentals
Core concepts
Candidates should be comfortable with Newton's three laws, work-energy-power relations, the difference between mass and weight, and the behaviour of waves (reflection, refraction, diffraction). In chemistry, know atomic structure, the periodic table trends (atomic radius, electronegativity, ionisation energy), ionic versus covalent bonding, balancing equations, the mole concept, and acid-base behaviour including pH.
Common traps
- Confusing mass (kg, invariant) with weight (N, depends on gravity).
- Mixing up speed and velocity, or scalar and vector quantities.
- Assuming heavier objects fall faster in a vacuum; they do not.
- Forgetting that pH is logarithmic: a change of one unit means a tenfold change in hydrogen-ion concentration.
- Treating a catalyst as a reactant that is consumed; it is not.
Worked example and rule of thumb
Rule of thumb: for uniform acceleration, use v = u + at and s = ut + ½at². Example: a body starts from rest and accelerates at 2 m/s² for 5 s. Final velocity = 0 + 2×5 = 10 m/s; distance = 0 + ½×2×5² = 25 m. For chemistry calculations, always convert to moles first (n = mass ÷ molar mass), then use the balanced equation's stoichiometric ratio. Check units at every step; most exam errors are unit slips rather than conceptual ones.