1. Coefficient
Since it is a number that constant for the given substance
False, in all methods of charge transfer, friction, conduction, and induction, they all require at least contact between the objects.
Answers to wave questions:
1) trough - lowest point of the wave.
2) crest - highest point of wave.
3) amplitude - distance from rest position to the crest or thoughs.
4) wavelenght - distance from two consecutive crest or troughs.
5) rest position - the flat line running through middle of the wave.
<u>Answer:</u> The hydrogen ion concentration of his saliva is 
<u>Explanation:</u>
pH is defined as the negative logarithm of hydrogen ion concentration present in the solution.
To calculate the pH of the solution, we use the equation:
![pH=-\log[H^+]](https://tex.z-dn.net/?f=pH%3D-%5Clog%5BH%5E%2B%5D)
We are given:
pH of the saliva = 6.1
Putting values in above equation, we get:
![6.1=-\log[H^+]](https://tex.z-dn.net/?f=6.1%3D-%5Clog%5BH%5E%2B%5D)
![[H^+]=10^{-6.1}=7.94\times 10^{-7}M](https://tex.z-dn.net/?f=%5BH%5E%2B%5D%3D10%5E%7B-6.1%7D%3D7.94%5Ctimes%2010%5E%7B-7%7DM)
Hence, the hydrogen ion concentration of his saliva is
Parabolic and they use it because light hits your face (the focal point) and gets reflected in the mirror. The concave, or parabolic, shape of the mirror surface concentrates the light beams, intensifying light as it gets closer to the focal point! :)
