Year 10 Science Exam Study Guide: Waves, Space, and the Universe

Comprehensive vocabulary flashcards covering the Year 10 Science exam curriculum: Wave properties and types, astronomical units, stellar life cycles, space observation technologies, and the Big Bang Theory.

Wave

A disturbance that transfers energy from one place to another without transferring matter overall.

Transverse wave

A wave in which oscillations or particle vibrations are perpendicular to the direction in which the wave transfers energy.

Longitudinal wave

A wave in which oscillations or particle vibrations are parallel to the direction in which the wave transfers energy.

Crest

The highest point of a transverse wave.

Trough

The lowest point of a transverse wave.

Amplitude

The maximum displacement of a wave from its resting or equilibrium position.

Wavelength

The distance between corresponding points on consecutive waves, represented by the symbol $\lambda$ and measured in metres ($\text{m}$).

Compression

A region in a longitudinal wave where particles are close together.

Rarefaction

A region in a longitudinal wave where particles are spread apart.

Frequency

The number of complete waves or cycles passing a point each second, represented by $f$ and measured in hertz ($\text{Hz}$).

Wave speed

The distance travelled by a wave per second, calculated using the formula $v = f \times \lambda$ and measured in metres per second ($\text{m/s}$).

Period

The time taken for one complete wave oscillation, represented by $T$ and measured in seconds ($\text{s}$).

Electromagnetic waves

Waves that transfer energy through oscillating electric and magnetic fields and can travel through a vacuum.

Electromagnetic spectrum

The complete range of electromagnetic radiation arranged from longest to shortest wavelength: Radio, Microwave, Infrared, Visible light, Ultraviolet, X-rays, and Gamma rays.

Doppler effect

The apparent change in the observed frequency or wavelength of a wave due to relative motion between the source and the observer.

Redshift

The shift of an object's spectral lines towards longer wavelengths, indicating that the object is moving away from the observer.

Blueshift

The shift of an object's spectral lines towards shorter wavelengths, indicating that the object is moving towards the observer.

Astronomical unit (AU)

A unit of distance equal to the average distance between Earth and the Sun, approximately $150\text{ million km}$, used primarily within our Solar System.

Light-year (ly)

A unit of distance equal to the distance light travels through a vacuum in one year, approximately $9.46 \times 10^{12}\,\text{km}$.

Stellar parallax

The apparent change in position of a nearby star relative to distant background stars when observed from opposite sides of Earth's orbit six months apart.

Star

A massive, luminous ball of hot plasma held together by gravity that generates energy through nuclear fusion in its core.

Planet

A celestial body that orbits a star directly, does not produce its own light through sustained nuclear fusion, and generally shines by reflecting light.

Moon

A natural satellite that orbits a planet or another planetary body and reflects sunlight.

Asteroid

A small rocky or metallic body orbiting the Sun.

Comet

An icy body orbiting the Sun that can release gas and dust, forming a glowing coma and tails as it is heated.

Meteoroid

A relatively small natural object travelling through space.

Meteor

The streak of light produced when a meteoroid enters an atmosphere and heats up.

Meteorite

Material from space that survives passage through an atmosphere and reaches the ground.

Nebula

A cloud of gas and dust in space that can serve as a nursery for new stars or result from material expelled by dying stars.

Galaxy

A vast system of stars, gas, dust, and dark matter held together by gravity.

Apparent magnitude

A measure of how bright a celestial object appears when observed from Earth.

Absolute magnitude

A measure of the intrinsic brightness of a celestial object if it were placed at a standard distance of $10\,\text{parsecs}$.

Protostar

An early stage of stellar evolution formed when gravity collapses material inside a nebula, creating an increasingly hot and dense core.

Nuclear fusion

The process occurring in stellar cores in which light atomic nuclei combine to form heavier nuclei, releasing energy.

Main sequence

The stable life stage of a star where inward gravitational pull is balanced by outward pressure generated by the fusion of hydrogen into helium.

Red giant

The stage of a low- or intermediate-mass star when core hydrogen is depleted, causing the core to contract and heat while the outer layers expand and cool.

Planetary nebula

An expanding shell of gas expelled into space by an aging low- or intermediate-mass star around its remaining core.

White dwarf

The hot, dense core remnant of a low- or intermediate-mass star that no longer generates energy via sustained nuclear fusion.

Red supergiant

An expanded late stage of a massive star where successive core fusion stages produce heavier elements up to iron.

Supernova

A colossal explosion triggered by the core collapse of a massive star that releases enormous energy and distributes elements into space.

Neutron star

An extremely dense stellar remnant composed mainly of neutrons, formed after the core collapse of a massive star.

Black hole

A stellar remnant formed from the core collapse of a sufficiently massive star with gravity so strong that light cannot escape from inside its event horizon.

Optical telescope

An astronomical instrument designed to collect and focus visible light using lenses (refracting) or mirrors (reflecting).

Radio telescope

An instrument, usually featuring a large dish antenna, that detects radio waves emitted by astronomical objects.

Space telescope

An astronomical observatory placed in orbit above Earth's atmosphere to bypass atmospheric distortion and observe wavelengths absorbed by the air.

Satellite

Any natural or artificial object that orbits a larger celestial body.

Space probe

An uncrewed robotic spacecraft carrying scientific instruments sent to travel through space, fly past, orbit, or land on celestial bodies.

Rover

A mobile robotic vehicle designed to navigate across the solid surface of a celestial body to gather direct samples and measurements.

Big Bang Theory

The leading scientific model stating that the universe expanded from an extremely hot, dense state approximately $13.8\text{ billion years}$ ago and continues to expand and cool.

Cosmic Microwave Background (CMB) radiation

Faint thermal microwave radiation at approximately $2.7\,\text{K}$ filling the universe, left over from when neutral atoms first formed around $380,000\text{ years}$ after the Big Bang.

Hubble–Lemaître law

The astronomical principle stating that the recession speed of distant galaxies is proportional to their distance ($v = H_0 \times d$).