General Science
Physics essentials
- SI units and symbols; scalars versus vectors.
- Newton's three laws and conservation of momentum.
- Work, power and energy; Ohm's law V = IR; series and parallel resistances.
- Reflection and refraction; sound needs a material medium to travel.
Chemistry essentials
- Atomic number = number of protons; mass number = protons + neutrons.
- Periodic-table families: alkali metals, halogens, noble gases.
- Acids turn blue litmus red; pH below 7 is acidic, above 7 is basic.
- Common formulae: H₂SO₄, NaCl, CaCO₃, NaHCO₃ (baking soda), CaO (quicklime).
Biology essentials
- Cell organelles and their functions; plant cell versus animal cell.
- Human systems: digestive, respiratory, circulatory, nervous.
- Vitamins and deficiency diseases: A – night blindness, B1 – beriberi, C – scurvy, D – rickets.
- Malaria (Plasmodium, spread by Anopheles mosquito), tuberculosis (bacteria), dengue (virus, Aedes mosquito).
Worked example
A 12 V battery is connected across a 4 Ω resistor. From V = IR, the current is I = V/R = 12/4 = 3 A. Power = VI = 12 × 3 = 36 W. Check the units: volts divided by ohms gives amperes, as expected.
Traps that cost marks
- Mass versus weight - weight = mg and is measured in newtons.
- Speed versus velocity - velocity carries direction.
- Assuming every acid is strong; acetic acid is weak.
- Confusing the causative agent of a disease with its vector.