Radiation and Waves (OCR)

What is radiation as a model?

A model that explains how energy is transferred from a source to an object some distance away.

What is the electromagnetic spectrum?

A range of different types of electromagnetic radiation including radio waves, microwaves, infrared, visible light, ultraviolet, X-rays, and gamma rays.

How does radiation interact with matter?

Radiation can be transmitted, reflected, or absorbed.

What is the speed of light in a vacuum?

Approximately 3 × 10⁸ meters per second.

What are three effects when radiation strikes an object?

It can be transmitted, reflected, or absorbed.

What happens when radiation is absorbed by an object?

The object usually heats up.

Which forms of radiation can cause ionization?

X-rays, gamma rays, and high-energy ultraviolet radiation.

What are two benefits of using electromagnetic radiation?

Medical imaging (e.g., X-rays) and communication technologies (e.g., radio, microwaves).

What is a risk associated with ionizing radiation?

It can damage living tissue and may lead to mutations or increase cancer risk.

What can high doses of ionizing radiation cause?

Damage or destroy living cells, potentially leading to radiation sickness or death.

What do ozone layers do?

They absorb harmful ultraviolet (UV) radiation from the sun.

What are radio waves produced by?

Oscillating currents in electrical circuits.

Why are microwaves used for heating?

Because they are absorbed by water molecules.

What are two key factors for evaluating new technologies?

Consider both benefits and potential risks, and use data and scientific explanations.

What happens to cooler objects in terms of emitted wavelength?

They emit longer wavelengths, such as infrared.

What is black body radiation?

An ideal object that absorbs and emits all radiation perfectly.

What is the greenhouse effect?

Gases in the atmosphere trap heat by absorbing and re-emitting infrared radiation.

What can happen if an object absorbs more radiation than it emits?

It gets hotter.

What gases contribute to the greenhouse effect?

Carbon dioxide, methane, and water vapor.

How does cloud cover affect Earth’s temperature?

Clouds can reflect or trap radiation depending on their type and height.

What evidence supports climate change?

Rising carbon dioxide levels due to human activities like burning fossil fuels and deforestation.

What is the purpose of computer climate models?

To predict temperature rises and understand long-term climate trends.

How is a wave defined?

A regular disturbance that transfers energy through a medium or space.

Do waves transfer matter or energy?

Waves transfer energy, not matter.

What demonstrates the behavior of transverse waves?

Particles in the medium move at right angles to the wave direction.

Give an example of a longitudinal wave.

Sound waves in air.

What does amplitude represent in a wave?

Maximum displacement from the rest position, linked to the energy carried by the wave.

What is wavelength?

Distance between two matching points on a wave.

What does frequency measure?

The number of waves passing a point each second.

What occurs during reflection?

Waves bounce back when they hit a surface.

What causes refraction in waves?

A change in wave speed when passing from one medium to another.

What happens to the frequency during refraction?

The frequency stays constant.

What are the two types of waves?

Transverse waves and longitudinal waves.

What is an example of wave refraction?

Light bending when it enters glass from air.

What are electromagnetic waves?

Transverse waves that include radio waves, microwaves, infrared, visible light, ultraviolet, X-rays, and gamma rays.

How do electromagnetic waves travel?

They do not need a medium and can move through a vacuum.

What is the speed of all electromagnetic waves in a vacuum?

Approximately 3.0 × 10⁸ meters per second.

What is one property of all electromagnetic waves?

They are all transverse.

What are two key points about refraction?

Wavelength and speed change depending on the medium; frequency remains constant.

What effect does solar activity have on Earth?

Changes in the Sun's output affect incoming energy.

How can excessive exposure to ultraviolet radiation affect health?

It may cause skin damage or eye problems.

What should be considered when assessing new technologies using electromagnetic spectrum?

Both benefits and potential risks.

What is necessary for an object to maintain a constant temperature?

The rate of incoming radiation equals the rate of radiation emitted.