Year 8 Physics – Am I Safe? Energy and Radiation

Flashcards covering key concepts from the lecture notes on Energy, Radiation, Atomic Structure, and Ionizing Radiation. Topics include types of energy, conservation of energy, radiation types, atomic structure, ionization, nuclear radiation, radioactive decay, half-life, radiation risks, and safety measures.

Energy

The ability to do work.

Potential Energy

Energy stored due to position or condition.

Kinetic Energy

Energy of motion.

Gravitational Potential Energy

A store of energy due to the position or place.

Kinetic Energy

The energy of motion.

Chemical Potential Energy

The energy stored in the bonds of atoms and molecules.

Sound Energy

A vibrational energy that produces sound.

Nuclear Potential Energy

The energy stored within the nucleus of atoms.

Light Energy

An electromagnetic energy that travels in waves.

Elastic Potential Energy

The energy stored under tension.

Heat or Thermal Energy

The internal energy of substances that is released during activity/movement.

Electrical Potential Energy

The electrical energy that can be transferred between particles.

Law of Conservation of Energy

Energy can only be transformed or transferred, but not created or destroyed (except in a nuclear reaction).

Radiation

The transfer of energy via particles or waves.

Mechanical Waves

Waves that travel via particle oscillation and require a medium to propagate.

Medium

Any substance that waves travel through.

Transverse Mechanical Waves

Particles of the medium oscillate in a direction that is perpendicular to the direction the wave is travelling.

Longitudinal Mechanical Waves

Particles of the medium oscillate in a direction parallel to the direction the wave is travelling.

Electromagnetic Waves

Waves that travel via light and do not require a medium to propagate.

Electromagnetic Wave Energy Relationship

As the wavelength of an electromagnetic wave increases, the energy of the wave decreases.

Radio Waves

Very low energy, used to send radio and television transmissions

Microwave

Low energy, used to send wi-fi and Bluetooth signals.

Infrared

Fairly low energy, transfers heat from one place to another and detected by infrared cameras.

Visible Light

The only kind of EM wave that humans can see with their eyes.

Ultraviolet

Fairly high energy, used in 'black lights' higher energies can be harmful to skin.

X-ray

High energy, can pass through soft tissues, but is absorbed by hard tissues like bones.

Gamma Ray

Very high energy, produced in the Sun, but mostly blocked by Earth's atmosphere.

Atoms

Particles that make up atoms: Protons Neutrons and Electrons

Atomic Number

The number of protons in the nucleus of an atom of an element.

Mass Number

The total number of protons and neutrons in the nucleus of an atom.

Isotopes

Atoms with the same number of protons, but a different number of neutrons.

Ion

A particle with an unequal number of protons and electrons.

Ionizing Radiation

Radiation with high enough energy to remove an electron from its atom.

Nuclear Radiation

Radiation that is emitted from the nucleus of an atom.

Unstable Nucleus

An atomic nucleus will emit nuclear radiation if it is unstable (has too much energy).

Alpha Particles

Two protons and two neutrons – a total relative mass of 4 and a relative charge of +2.

Beta Particles

Electrons with very high energy (very high speed) – a relative mass of 1/2000 and a relative charge of -1.

Gamma Rays

Very high-energy electromagnetic waves – have no mass and no charge.

Penetration Ability

Radiation's ability to penetrate through matter.

Ionization Ability

Radiation's ability to ionize atoms.

Radioactive Decay

The process by which an unstable parent nucleus transmutes into a daughter nucleus by emitting nuclear radiation.

Parent Nucleus

The unstable nucleus which undergoes radioactive Decay

Daughter Nucleus

The resulting nucleus after radioactive decay.

Alpha Decay

Two protons and two neutrons break off the unstable parent nucleus form the alpha particle.

Beta Decay

One electron (which is emitted). One neutron in the unstable parent nucleus transmutes into one proton (which stays in the nucleus)

Gamma Decay

Gamma radiation (The neutrons and protons in the nucleus rearrange into a more stable configuration)

Half-Life

The time taken for half of the radioactive nuclei in a sample to decay.

Radiation Risk

Dependent on type of radiation, distance from source, and exposure time.

Reduce Radiation Exposure

Increase shielding, increase distance, and decrease exposure time.