Basic Science (Physics, Chemistry, Biology)
Basic Science here is school-level physics, chemistry and biology applied to laboratory work: units and measurement, motion, acids and bases, the periodic table, cells and human body systems.
Physics
- SI base units: metre, kilogram, second, ampere, kelvin, mole, candela. Force in newtons, energy in joules, power in watts, pressure in pascals.
- Speed = distance / time; 1 km/h = 5/18 m/s.
- Newton's laws of motion; work = force x displacement along the force.
Chemistry
- Atomic number = number of protons; mass number = protons + neutrons.
- pH below 7 is acidic, 7 neutral, above 7 basic; acids turn blue litmus red.
- Molarity = moles of solute / litres of solution.
- Common formulae: H2SO4, HCl, NaOH, NaHCO3, NaCl; the molar mass of water is about 18 g/mol.
Biology
- The cell is the structural and functional unit; mitochondria are the powerhouse; chloroplasts carry out photosynthesis, 6CO2 + 6H2O giving C6H12O6 + 6O2.
- Blood groups are A, B, AB and O; O negative is the universal donor.
Worked example
A car covers 150 km in 3 hours. Speed = 150 / 3 = 50 km/h. In SI units: 50 x 5/18 is about 13.9 m/s. Check: 13.9 m/s x 3600 s = 50,040 m, roughly 50 km, which confirms the conversion.
Traps
Swapping mass number and atomic number; rounding g to 10 m/s squared when the options differ; using the volume of solvent instead of the final solution volume for molarity; treating viruses as bacteria.