Integrated Science - Unit 1: Aquatic Ecosystems

Comprehensive vocabulary flashcards covering the environment, hydrosphere, water cycle, chemical properties of water, and physical properties of water from Unit 1.

Environment

An integrated system whose parts cannot be separated because they constantly affect each other, originating from the French word 'Environ', meaning 'what surrounds us'.

Abiotic factors

The physical and chemical elements of the environment, such as light, air, water, and soil.

Biotic factors

The biological elements of the environment, including humans, plants, animals, and microorganisms.

Ecosystem

A community of living organisms that interact with each other and with non-living components, in order to adapt to changeable conditions.

Hydrosphere

The water that exists on planet Earth, covering about $70\%$ of Earth's surface.

Water cycle (hydrological cycle)

The continuous movement of water present on or near the Earth's surface from one place to another around the Earth, in a nearly closed system, through many different pathways while changing among solid, liquid, and gas states.

Infiltration

The water cycle process by which water leaks through soil pores and sedimentary rocks to form groundwater.

Transpiration

The biological process by which a plant gets rid of excess water as vapor from its surface exposed to the air, primarily through stomata.

Stomata

Microscopic openings on leaves and green stems through which most plant transpiration occurs.

Excretion

The process by which living organisms eliminate waste products resulting from metabolic processes, such as carbon dioxide, water vapor, and nitrogenous wastes.

Covalent bond

A chemical bond that joins two atoms by sharing electrons, where each atom shares one or more electrons to form the bond.

Electronegativity

A measure of an atom's ability to attract the electrons of a chemical bond towards itself for a longer period of time.

Hydrogen bond (among water molecules)

An electrostatic attraction between the partially positive hydrogen atom ($\delta^+$) of one water molecule and the partially negative oxygen atom ($\delta^-$) of a neighbouring water molecule.

Hydrolysis of salts

A reaction that happens when a solid salt dissolves in water and forms an acid and a base, one or both of which are weak ($\text{Water} + \text{Salt} \rightarrow \text{Acid} + \text{Base}$).

Neutral salts

Salts that dissolve in water leaving the concentration of hydrogen ions equal to hydroxide ions ($[H^+] = [OH^-]$), resulting in a neutral solution ($\text{pH} = 7$), such as ammonium bicarbonate ($NH_4HCO_3$).

Basic salts

Salts that dissolve in water resulting in a decrease in $[H^+]$ and an increase in $[OH^-]$, forming an alkaline solution ($\text{pH} > 7$), such as sodium bicarbonate ($NaHCO_3$).

Acidic salts

Salts that dissolve in water resulting in an increase in $[H^+]$ and a decrease in $[OH^-]$, forming an acidic solution ($\text{pH} < 7$), such as ammonium chloride ($NH_4Cl$).

pH value (pH scale)

A quantitative measurement, with values ranging from $0$ to $14$, that expresses the acidity, neutrality, or alkalinity of a liquid or solution based on the balance between $H^+$ and $OH^-$ ions.

Fluid

Any substance that can flow and has no fixed shape, but takes the shape of its container, such as liquids and gases.

Density

A characteristic physical property defined as the mass of a unit volume of matter at a given temperature, calculated as $\rho = \frac{m}{V}$.

Relative density

The ratio of the density of a substance at a given temperature to the density of pure water at $4\,^\circ\text{C}$, which is a dimensionless quantity equal in magnitude to density in $\text{g/cm}^3$.

Hydrometer

A device based on the law of buoyancy used for measuring the density and relative density of liquids, featuring a graduated glass stem and a weighted cylindrical bulb.

Ocean currents

The movement of water from one region to another, carrying heat, salt, nutrients, and fresh water across the globe, driven partly by differences in water density.

Internal energy

The sum of the kinetic and potential energies of the molecules composing a system or body.

System

A definite portion of the physical universe chosen for study, such as a metal sphere or liquid in a beaker.

Temperature

A quantitative description of how hot or cold a body or system is, representing a measure of the average kinetic energy of its molecules.

Absolute zero

The lowest possible temperature, defined as $0\,\text{K}$ or $-273\,^\circ\text{C}$, where the kinetic energy of molecules becomes zero.

Amount of heat

The thermal energy transferred from, to, or through a body when there is a difference in temperature, measured in joules ($\text{J}$).

Specific heat

The amount of heat required to raise the temperature of $1\,\text{kg}$ of a substance by one degree Celsius ($1\,^\circ\text{C}$) or one kelvin ($1\,\text{K}$), with units of $\text{J}\,\text{kg}^{-1}\,\text{K}^{-1}$.

Poikilotherms

Cold-blooded organisms whose body temperature depends on the surrounding temperature, often living in deep seas and oceans where temperatures remain relatively stable.

Warm-blooded organisms

Organisms that maintain their body temperature through metabolic processes, independent of the surrounding environment, such as birds and mammals.

Latent heat of vaporization

The heat energy absorbed by a unit mass ($1\,\text{kg}$) during its conversion from liquid to gas (or released during condensation) without a change in temperature, measured in $\text{J/kg}$.