SPM Additional Science flashcards
SPM Additional Science · Build recall with a focused review session.
32 cards. Read the term and the definition here. The deck at the top of this page is optional.
- Hypothesis
- A testable statement predicting the relationship between the manipulated and responding variables, which can be accepted or rejected based on experimental evidence.
- Accuracy vs precision
- Accuracy describes how close a measurement is to the true value; precision describes how close repeated measurements are to one another.
- SI base units
- The seven fundamental units: metre, kilogram, second, ampere, kelvin, mole, candela. All other SI units are derived from these.
- Random error
- An unpredictable variation in readings caused by environmental or human factors, reduced by taking multiple readings and calculating the mean.
- Nucleon number
- The total number of protons and neutrons in a nucleus, also called mass number, and represented by the letter A.
- Isotopes
- Atoms of the same element with the same proton number but different neutron numbers, giving identical chemical properties but different atomic masses.
- Ionic bond
- The electrostatic attraction between oppositely charged ions formed when a metal atom transfers electrons to a non-metal atom.
- Diffusion
- The net movement of particles from a region of higher concentration to a region of lower concentration, due to random particle motion.
- Mole
- The amount of substance containing 6.02 × 10^23 particles; the mass of one mole equals the molar mass in grams.
- OIL RIG
- A mnemonic for redox: Oxidation Is Loss of electrons, Reduction Is Gain of electrons.
- Catalyst
- A substance that increases the rate of a reaction by providing an alternative pathway with lower activation energy, without being consumed.
- Neutralisation
- The reaction between an acid and a base to form a salt and water, producing a solution closer to neutral pH.
- Newton's second law
- The acceleration of an object is directly proportional to the net force acting on it and inversely proportional to its mass, F = ma.
- Conservation of momentum
- In a closed system, the total momentum before a collision or explosion equals the total momentum after it.
- Efficiency
- The ratio of useful energy output to total energy input, usually expressed as a percentage; the remainder is wasted as heat.
- Hooke's law
- The extension of a spring is directly proportional to the applied force, provided the elastic limit is not exceeded.
- Ohm's law
- The current through a conductor is directly proportional to the voltage across it, provided temperature remains constant, giving V = IR.
- Parallel circuit
- A circuit in which components are connected across the same voltage; current splits between branches and total resistance is less than any branch.
- Electromagnetic induction
- The production of an electromotive force in a conductor when the magnetic flux linking it changes, as in a generator.
- Transformer
- A device using mutual induction between two coils to change alternating voltage; the turns ratio equals the voltage ratio.
- Total internal reflection
- The complete reflection of light inside a denser medium when the angle of incidence exceeds the critical angle defined by sin c = 1/n.
- Refraction
- The change in direction of a wave as it passes between media of different optical density, caused by a change in wave speed.
- Resonance
- A phenomenon where an object vibrates with maximum amplitude when driven at its natural frequency by an external periodic force.
- Photosynthesis
- The process in chloroplasts using chlorophyll and light energy to convert carbon dioxide and water into glucose and oxygen.
- Enzyme
- A biological catalyst, usually a protein, that speeds up reactions by lowering activation energy and is specific to its substrate.
- Osmosis
- The net movement of water molecules across a semi-permeable membrane from a region of higher to lower water potential.
- Reflex arc
- The neural pathway from receptor through sensory, relay and motor neurones to effector that produces a rapid involuntary response.
- Negative feedback
- A control mechanism in which a change in a body variable triggers a response that reverses the change, restoring the set point.
- Ovulation
- The release of a mature ovum from an ovary, triggered by a surge of luteinising hormone around the midpoint of the menstrual cycle.
- Trophic level
- The position of an organism in a food chain, such as producer or primary consumer, determined by how it obtains energy.
- Eutrophication
- Nutrient enrichment of water by nitrates and phosphates causing algal blooms, oxygen depletion and death of aquatic organisms.
- Semiconductor
- A material such as silicon whose conductivity lies between conductors and insulators and increases when doped with impurities.