Stage 5 Science: Materials Study Notes

Vocabulary practice flashcards covering organic chemistry, hydrocarbons, combustion reactions, polymers, finite resources, and scientific investigation skills.

Organic Compounds

Chemical compounds that always contain carbon atoms covalently bonded to hydrogen ($\text{C-H}$ bonds).

Inorganic Compounds

Compounds that typically do not contain carbon-hydrogen bonds, such as $CO_2$, $H_2O$, and $NaCl$.

Fractional Distillation

The industrial separation method inside a fractionating tower that separates hydrocarbon mixtures based on differences in their boiling points across a temperature gradient.

Alkanes

Saturated hydrocarbons containing exclusively single covalent bonds between carbon atoms, characterized by the general molecular formula $C_n H_{2n+2}$.

Complete Combustion

A combustion reaction occurring in a plentiful supply of oxygen ($O_2$) that produces carbon dioxide ($CO_2$), water vapour ($H_2O$), a clean blue flame, and a high amount of energy.

Incomplete Combustion

A combustion reaction occurring when oxygen ($O_2$) supply is limited, generating toxic carbon monoxide ($CO$), carbon soot ($C$), water vapour ($H_2O$), a smoky yellow flame, and lower energy.

Carbon Monoxide ($CO$)

A toxic, colourless, and odourless gas produced by incomplete combustion, commonly referred to as a silent killer.

Soot ($C$)

Airborne toxic particulate carbon produced during incomplete combustion that damages human lungs, turns building walls black, and fouls internal engine parts.

Polymer

A massive, long-chain molecule formed by linking thousands of repeating smaller chemical building blocks called monomers.

Monomer

A small chemical building block (such as ethene gas derived from crude oil) that joins together by the thousands to form a polymer.

Low-Density Polyethylene (LDPE)

A flexible, lightweight, and transparent polymer composed of highly branched polymer chains that cannot pack closely together; commonly used for cling wrap, plastic shopping bags, and squeezable bottles.

High-Density Polyethylene (HDPE)

A rigid, strong, and highly durable polymer composed of long, linear, unbranched chains that align and pack tightly together; commonly used for milk crates, water pipes, and hard hats.

Finite Resources

Natural mineral resources (such as iron ore, bauxite, and coal) that exist in strictly limited quantities and are consumed drastically faster than natural geological processes can regenerate them.

Independent Variable

The parameter that is deliberately altered or manipulated by the experimenter during an investigation, always positioned on the graph's X-axis.

Dependent Variable

The operational outcome measured or observed to collect data during an investigation, always positioned on the graph's Y-axis.

Controlled Variables

Background elements that are kept strictly identical across all tested groups to guarantee a fair and valid experiment.

Interpolation

The process of estimating an unknown intermediate data value that sits entirely inside the boundaries of verified data points.

Extrapolation

The process of extending an observed graphical trend to predict future behavioral outcomes that lie entirely outside or beyond verified dataset parameters.

Reliability

An experimental quality established by conducting multiple repeated trials to achieve highly consistent results.

Validity

An experimental quality secured by ensuring the design directly tests the target hypothesis and independent variable while maintaining flawless control over all background variables.