Year 10 Science Comprehensive Review: Motion, Chemical Reactions, Electricity, Evolution, and the Scientific Method

Vocabulary practice flashcards covering Year 10 Science topics: Motion, Chemical Reactions, Electricity & Energy, Evolution & Geological Time, and the Scientific Method.

Speed

A scalar physical quantity that describes how fast an object is travelling, measured in metres per second ($m/s$ or $ms^{-1}$) or kilometres per hour ($km/h$).

Velocity

A vector quantity that describes both the speed and the directional path of an object's motion.

Distance ($d$)

A scalar measurement indicating the total path length traversed by an object during its motion, measured in metres ($m$).

Displacement ($s$)

A vector quantity representing the overall straight-line change in position from an object's starting point to its finishing point, specified with both magnitude in metres ($m$) and a direction.

Acceleration ($a$)

The rate of change of velocity or speed over time, calculated using the formula $a = \frac{v - u}{t}$ where $v$ is final speed, $u$ is initial speed, and $t$ is time taken, measured in metres per second squared ($m/s^2$ or $ms^{-2}$).

Inertia

The natural tendency of an object to resist any change in its state of rest or uniform motion.

Friction

A contact force that opposes the relative motion between two interacting surfaces, acting to slow objects down.

Newton's First Law of Motion

The principle stating that an object remains at rest, or continues to move with constant speed in the same direction, unless acted upon by an unbalanced external force (also known as the Law of Inertia).

Newton's Second Law of Motion

The law stating that the acceleration of an object is directly proportional to the magnitude of the net force acting on it and inversely proportional to its mass, expressed mathematically as $F = ma$.

Newton's Third Law of Motion

The law stating that for every action force exerted on a body, there is an equal and opposite reaction force exerted back simultaneously.

Momentum ($p$)

A vector quantity measuring the motion of a body, calculated as the product of mass and velocity ($p = mv$) and expressed in units of $kg\,m/s$.

Net Force

The vector sum of all individual forces acting upon an object, capable of causing an acceleration.

Crumple Zone

A structural vehicle safety zone engineered to deform progressively during a collision, absorbing kinetic energy and lengthening the deceleration time to reduce the net force delivered to passengers.

Ticker Timer

A laboratory timing instrument that records linear movement by using an electromagnetic arm vibrating at $50\,Hz$ to stamp carbon dots onto paper tape at intervals of one-fiftieth of a second ($0.02\,s$).

BUCKS Problem Solving Method

A structured mathematical and scientific strategy: Box the question, Underline the facts, Circle vocabulary and key words, Knock out unnecessary information, and State the Strategy, Operation, and Solve.

Chemical Reaction

A process involving the rearrangement of existing atoms where chemical bonds within reactants are broken and new bonds are formed to yield distinct products.

Balanced Chemical Equation

A representation of a chemical reaction using formulas and stoichiometric coefficients where the count of each atom type is identical on both sides, demonstrating the conservation of matter.

Corrosion

The chemical degradation of a metal through oxidation when exposed to oxygen, moisture, or electrolytes in its surroundings, forming compounds such as metal oxides.

Activity Series of Metals

An empirical ranking of metallic elements ordered from highest to lowest chemical reactivity, used to predict displacement and corrosion tendencies.

Sacrificial Protection

A corrosion mitigation technique where a more chemically active metal (such as zinc) is placed in electrical contact with a base metal (such as iron) so that it oxidises preferentially.

Alloy

A homogeneous metallic substance produced by combining a base metal with one or more other elements to enhance functional properties such as tensile strength, durability, or corrosion resistance.

Shape Memory Alloy

An alloy that deforms at lower temperatures but reverts to its predetermined original shape when heated above a specific transition temperature.

Nitinol

A biocompatible shape memory alloy composed of nickel and titanium utilized in medical interventions, such as self-expanding arterial filters designed to trap blood clots.

Precipitation Reaction

A reaction occurring in an aqueous medium in which two soluble salt solutions interact to produce an insoluble solid that settles out of solution.

Decomposition Reaction

A chemical reaction in which a single compound breaks down into two or more simpler elemental substances or compounds, generally requiring thermal, electrical, or radiant energy input.

Electrolysis

The application of an external direct electrical current to drive a non-spontaneous chemical decomposition, such as splitting liquid water ($H_2O$) into gaseous hydrogen ($H_2$) and oxygen ($O_2$).

Hydrocarbon

An organic chemical compound whose molecular structure consists entirely of bonded carbon and hydrogen atoms.

Alkane

A saturated hydrocarbon containing exclusively single carbon-carbon bonds, conforming to the general formula $C_nH_{2n+2}$.

Alkene

An unsaturated hydrocarbon containing at least one carbon-carbon double bond, conforming to the general formula $C_nH_{2n}$.

Alkyne

An unsaturated hydrocarbon containing at least one carbon-carbon triple bond, conforming to the general formula $C_nH_{2n-2}$.

Polymer

A macromolecule composed of thousands of repeating low-molecular-weight structural subunits called monomers joined by covalent bonds.

Biopolymer

A biodegradable polymer synthesized from plant or organic material that can be decomposed by micro-organisms, offering an environmentally safe alternative to synthetic plastics.

Electric Current ($I$)

The rate of flow of electric charge past a point in an electric circuit, measured in amperes ($A$) using an ammeter placed in series.

Voltage ($V$)

The measure of electrical potential difference or electric potential energy per unit charge between two points in a circuit, measured in volts ($V$) using a voltmeter connected in parallel.

Electrical Resistance ($R$)

The property of a component or material that opposes the flow of electric current through it, measured in ohms ($\Omega$).

Ohm's Law

The mathematical relationship establishing that electric current in a conductor is directly proportional to voltage and inversely proportional to resistance, written as $V = IR$.

Direct Current (DC)

An electrical current in which electrons flow continuously in one fixed direction through a conductor from negative to positive terminals.

Alternating Current (AC)

An electrical current in which electrons periodically alternate and shuttle back and forth along the conducting pathway.

Series Circuit

A circuit arrangement where electrical components are connected end-to-end along a single continuous loop, maintaining uniform current across all components while dividing total voltage.

Parallel Circuit

A circuit design where components are positioned across multiple distinct branches, preserving full source voltage across every branch while dividing total current.

Law of Conservation of Energy

A fundamental physical law stating that total energy within an isolated system remains constant over time; it cannot be created or destroyed, only transferred or transformed.

Energy Efficiency

The quantitative measure of the proportion of total input energy delivered to a system that is converted into useful output work or energy.

Renewable Energy

Energy collected from natural resources that replenish naturally on a human timescale and cannot be depleted, such as solar, wind, hydro, and geothermal energy.

Electromagnet

A temporary magnet produced by directing an electric current through a coiled conducting wire (solenoid), often wound around a ferromagnetic core to magnify the magnetic field.

Maglev Train

A transport vehicle propelled and levitated above a guideway through magnetic repulsion and attraction using superconducting electromagnets.

Natural Selection

The evolutionary mechanism in which inherited phenotypic variations conferring superior fitness in a given environment lead to differential survival and reproductive success.

Lamarckian Evolution

An early evolutionary hypothesis proposing that physical adaptations acquired by an organism through use or disuse during its lifespan can be directly transmitted to its offspring.

Darwinian Evolution

The scientific theory proposing that biological species descend with modification from common ancestors via natural selection acting upon random inherited variations.

Adaptive Radiation (Finch Beak Variation)

The rapid diversification of an ancestral species into distinct forms with specialized morphological adaptations, such as probing, grasping, or crushing beaks matched to distinct food niches across the Galapagos Islands.

Selective Pressure

Any external environmental factor (biotic like predation or disease, or abiotic like climate and temperature) that alters the reproductive success of specific phenotypes.

Speciation

The evolutionary process by which biological populations diverge through isolation and distinct selective pressures to form reproductively isolated species.

Law of Superposition

A foundational geological principle establishing that in undisturbed sedimentary rock strata, the lowest layers are the oldest and successively higher layers are progressively younger.

Index Fossil

A fossil of an organism that was abundant, geographically widespread, easily identifiable, and restricted to a short geological lifespan, used to date and correlate rock strata.

Absolute Dating

A radiometric dating method that establishes the numerical age of rock or fossil specimens based on the known decay rate of radioactive isotopes (such as Uranium-238 decaying to Lead-206).

Half-life

The specific time duration required for half of the radioactive parent nuclei in a sample to undergo radioactive decay into stable daughter products.

Geological Time Scale

A chronological system dividing Earth's $4.6\text{-billion-year}$ history into hierarchical units: eons, eras, periods, epochs, and ages.

Experimental Aim

A standardized formal statement beginning with the word 'to' that specifies the core purpose and objectives of an investigation.

Hypothesis

A testable predictive statement proposing an expected causal relationship between two or more measurable variables.

Independent Variable

The single factor or variable deliberately changed or manipulated by the experimenter to observe its effects.

Dependent Variable

The variable being observed and measured to assess the response caused by changes in the independent variable.

Controlled Variables

All parameters and external conditions in an experiment that are intentionally maintained constant to ensure a fair test.

Control Group

An experimental trial or group in which the independent variable is withheld or unchanged, serving as a baseline comparison.

Reliability

The consistency and reproducibility of experimental measurements across repeated trials conducted under identical conditions.

Validity

The extent to which an experiment accurately tests the stated aim and hypothesis by controlling all extraneous variables and eliminating systematic errors.

Safety Data Sheet (SDS)

A regulatory document provided by manufacturers detailing chemical hazards, handling instructions, safe storage, and emergency spill procedures.

PEEL Paragraph

A structured analytical writing format comprising Point (topic sentence), Explanation (detailed reasoning), Evidence (supporting data), and Link (connecting back to the prompt).