EM WAVES 2‼️

how are gamma rays produced

when there are changes to the nuclei of atoms

what happens when a gamma ray is emitted

the amount of nuclear energy stored within the nucleus decreases

USES of gamma rays

since they can penetrate body tissue easily, they are used for certain types of

-medical imaging (it is detected by special equipment when injected in the body to help observe some of the activities in the body using special equipment)

-radio therapy

-detection and monitoring of cancer

-treat cancer

-sterilizing food and surgical instruments

DISADVANTGES of gamma rays

• cause damage to body tissue

how are X Rays produced

The rapid deceleration of free electrons in an atom

Or by changes in the arrangement of the electrons orbiting the nucleus

Uses of X rays

Pass easily through soft tissue and absorbed effectively by bone(this is why we only see the bone x-rays in hospitals)

-medical imaging

-medical treatment( control or kill tumors because they can destroy and damage body tissue)

-airport security scanners

-investigating the internal structure of objects

3 Ultraviolet hazards

Sunburn

Skin cancer

Blindness

Uses of ultraviolet

It relies on a process called fluorescence

It absorbs ultraviolet radiation and instead emits longer wavelength visible light which is a wave on the EM spectrum just below ultraviolet

• the process is used in many types of energy saving light bulbs : so basically the electrical energy from the power supply causes the atoms in the light bulb to emit ultraviolet ray when these rays are absorbed by the fluorescent material which coat inside of the bulb visible light is emitted

• Security ink( used in bank notes or to identify stolen things)

• Smart water( criminals are covered in this substance, so they can be seen even weeks after their crimes)

• Disinfecting water

high frequency hazard involving gamma,X-rays and ultraviolet

The energy, these waves deposit in the body can ionize the atoms that make up cells

This means that they can lead to mutation which could cause cancer

however, they do not always cause cancer. If not, we wouldn’t have been using them all the time it’s more like the more gamma rays you’re exposed to the more danger it poses to yourselves.

uses of visible light

-what we use to see(human sight)-light energy detected by cells in the retina, which transfer energy to the brain that allows us to see

-lasers

-fire-optic communication systems

We receive visible light from both

Natural and artificial sources

Like the Sun and the lamp or candle

what objects emit infrared radiation

Objects at room temperature

The amount they emit increases the temperature

So it’s sometimes called thermal radiation

Uses of infrared

-electrical heaters and cookers

-fiber optic communications

-remote controls

-thermal imaging in infrared cameras (bases of night vision)

Uses of microwaves

-Cooking food

-mobile phone networks

-satellite communications (Gps systems) -microwaves are used because they pass easily through the earths atmosphere

-blue tooth

Uses of radio waves

-radio signals

-television signals

-used for radar

production of radio waves

they are produced by one antenna and detected by another

The transmitting antenna produces electrical input signals that oscillate the electrons up and down in the antenna which then produces radio waves that are traveled to the receiving antenna, The energy from the incident radio waves coming from the transmitting antenna, cause the electrons to oscillate up and down which is then detected as an electrical signal that carries it out to the receiver

CORE PRACTICAL

Investigating the radiation of infrared from a surface

1.

USING A LESLIE CUBE

1. the cube has four different types of surfaces on each vertical side; Shiny silver, Matt black, Matt white and shiny black

2. It has an opening in the top to which you would feel with hot water

3. Tape the cube

4. Point an infrared detector infront of one of the sides and take the reading to measure the amount of infrared taken by each surface

5. Do this for all the other four sides

6. Plot the results in a bar chart(this is because our Independent variable which is what we measure is categoric, which means that it is represented by words, not numbers)

7. The distance between each surface and the infrared detector must be the same

8. And the readings must be taking in as short intervals as we can; one after the other so the temperature of the water does not decrease by a significant amount

9. Shinier lighter color surfaces are poor emitters of infrared than darker Matt surfaces

1.

USING 2 BEAKERS

1. Fill 2 beakers with hot water

2. Cover one beaker with black sugar paper

3. Cover the other beaker with aluminum foil

4. Using a thermometer and a stop measure how their temperatures change with time

Investigating the ABSORBTION of infrared from a surface

1. Infrared radiation from an electrical heater is directed towards two metal sheets

2. One of the metal sheets should be a matte black surface and the other should be a shiny silver surface

3. On these two metal sheets, there will be drawing pins attached using wax

4. Start a timer using a stop clock when the two metal pins are attached safely

5. Using a stop clock measure the amount of time it takes for the drawing paint fall from each surface

6. In this experiment, we would expect the drawing pin in the shiny silver surface to fall fast because it is a poorer emitter of infrared radiation. It means that the maths black surface has absorbed more infrared radiation

7. Some control variables would be the same distance for both metal surfaces from the electrical heater

8. The same type of drawing pin to be used(weight of it)

9. The same amount of wax used and type of wax so that we ensure that the results can be comparable and fair