Daily Science pg Grab the National geographic article we read in class last time. Finish your paragraphs. If you are finished, make sure you have included 5 vocabulary words and have highlighted or circled them. 2. Next, I want you to write a paragraph on whether or not you believe the experiment the scientists did was ethical. Support your reason. Suggest one thing the scientists could have changed to better their experiment.

The Ear pg. 54

Light Pg. 55

Behavior of Light Light acts as both a wave and a particle. When passed through slits, light waves were seen to act like a wave by producing interference patterns.

Light as a wave The wave model describes light as transverse waves. They are called electromagnetic because they consist of changing electric and magnetic fields. Model also explains why light reflects, refracts, and diffracts.

Light as a stream of particles Scientists performed experiments and saw that light acted like energy contained in small packets. The particle model of light refers to the ‘packets of energy’ as photons. Photons do not have mass. Energy in a photon is located in a specific area.

Energy of light The energy of light is proportional to the frequency. The lower the frequency, the less energy contained in the light. Ex.: red light contains 3.0 x J of energy and has a frequency of 4.5 x Hz. Ultraviolet light has twice as much energy, therefore the frequency of UV light is twice as much as red light.

Speed of Light In a vacuum: 3.0 x 10 8 m/s In air: x 10 8 m/s In ice 2.29 x 10 8 m/s In diamond: 1.24 x 10 8 m/s

Brightness of light Intensity determines the brightness. In light, intensity is the number of photons per second that pass through a certain area. Intensity decreases as you move away from a source.

The Electromagnetic Spectrum Consists of waves at all possible energies Radio waves are the lowest frequencies. Radar is a system that uses radio waves to find the location of objects Microwaves are next on the spectrum Infrared light is slightly bigger than visible light. Can be felt as warmth Then there is visible light. Ultraviolet light has a frequency greater than visible light. X-rays and gamma rays have the highest frequencies.

Electromagnetic spectrum

Ultraviolet light Comes from the sun The Ozone protects us from it Can cause sun burns

X-rays and Gamma Rays X-rays have such a high frequency that they can pass through tissues and bones. Gamma rays have the highest energy and can be used to treat cancer.