Demonstrate your knowledge of waves. describe the difference between mechanical and electromagnetic waves. give an example of each kind of wave related to telecommunications. answer using complete sentences and key vocabulary

There are some methods that differentiate waves; one thing is by its medium. Electromagnetic waves did not require a medium for transmission such as in a vacuum while mechanical waves require a medium to travel such as air, water or anything that can serve as a transmission aid.  

The most common sample of EM waves in telecommunication is radio, light and infra-red signals. An example of a mechanical wave is a sound wave, which requires air to travel. Oscillating molecules made the sound waves. 

since the atomic number is the number of protons in the nucleus, as we move to the left on the periodic table, the electrostatic pull between the nucleus and the valence electron shell decreases. as we move down a group (vertical column), the valence shell energy level gets further and further from the nucleus.

when [oh-] is 10-5  m, and [h3o+] is 10-9  m, the poh is 5 and ph is 9. again in both cases the sum of ph and poh is 14. however, the hydrogen ion concentration is not always going to be equal to exactly 1 x 10 raised to a negative number. for example, we skipped over the value of 2.0 x 10-7.