Unit 3- Electromagnetic and Particulate Radiation

Properties of Electromagnetic energy

1) No mass

2) Exists as electric and magnetic disturbances

c=fxlambda

equation relating frequency (f), wavelength (lambda), c

E=h(frequency)

energy equation

Planck's constant

4.135x10^-15eVs

What is a photon?

a particle of electromagnetic radiation having zero mass and carrying a quantum of energy

Where does Electromagnetic Energy originate from?

1)At atom when electrons transition between orbital shells

2)Atomic nuclei emit excess energy to become stable

3)High-speed electrons come close to the nucleus.

Wave formula

v=fλ

Frequency and wavelength are ____ proportional

inversely

Energy is ______ proportional to wavelength.

inversely

Energy is _____ proportional to frequency

directly

3 Important Sections of Spectrum

1)X-rays and gamma rays eV(energy)

2)Visible Light nm(wavelentgh)

3)Radio-frequencies Hz(frequency)

X-rays and gamma rays are

ionizing radiation

X-ray & gamma rays have ______ E, ______ λ, and _______ frequencies than other EM.

1)Higher energy

2)Smaller wavelengths

3)Higher frequencies

What are the atom and electron removed called?

Electron pair

What is the difference between x-rays and gamma rays?

Origin

Where do x-rays come from?

Outside the nucleus/Electron clouds

Where do gamma rays come from?

inside the nucleus of a radioactive atom

What do the wavelengths of photons determine?

1)What they interact with

2)How they interact

Wave Model: Lower energy EM acts like ___

Waves

Interacts with Molecules and Cells

Particle Model: Higher energy EM acts like ___

Particles

Interacts with atoms

Visible Light Transmission

The percentage of visible light that is transmitted through the window

Visible Light Reflection

the process where light waves bounce off a surface instead of passing through or being absorbed by it

Visible Light Absorption

Absorption of a given range of wavelengths of visible light means the corresponding reflection of other colors.

Visible Light Attenuation

the reduction of light's intensity as it passes through a medium

Radiopaque

substance does not allow x-rays to pass through and appears white or light gray on the resulting film

Radiolucent

a substance that allows x-rays to pass through and appears black or dark gray on the resulting film

Inverse Square Law

the intensity of radiation is inversely proportional to the square of the distance from the source of radiation

X-rays are electrically

neutral

X-rays travel in ____ lines

straight

X-rays travel at

speed of light in a vacuum

X-rays cannot be

focused by a lens

Radioisotopes

Isotopes that have unstable nuclei and undergo radioactive decay.

Radionuclides

substances that emit radiation spontaneously; also called tracers

Beta Emissions

an electron created in the nucleus is emitted and a neutron converts into a proton changing the element

Alpha Emissions

decay of the nucleus by emitting an alpha particle

alpha particle: high-energy particle that contains 2 protons and 2 neutrons

+2 charge and a mass number of 4

Radioactive Half-Life

the time it takes for half of the radioactive isotopes in a sample to decay to a new form

5 Characteristics of Ionizing Radiation

Mass

Energy

Velocity

Wavelength

Frequency