Answer:
They are used because of preference or convenience, not necessity. These scales came about historically when there were no standards to calibrate a thermometer against. The Fahrenheit scale used the temperature of the coldest thing then known for its zero, which was salty ice.13-Oct-2019
<em><u>Answer:</u></em>
The Beaufort scale measures wind speed.
<em><u>Explanation:</u></em>
One way to measure wind speed is by observing its effects on objects. In 1805, a British naval officer named Sir Francis Beaufort developed a wind speed scale that refers to the movement of objects. The Beaufort Scale is a good way to introduce your students to the concept of wind speed.
<u>Answer:</u> The pH of the solution is 9.71
<u>Explanation:</u>
1 mole of NaOH produces 1 mole of sodium ions and 1 mole of hydroxide ions.
We are given:
pOH of the solution = 7.2
To calculate the pH of the solution, we need to determine pOH of the solution. To calculate pOh of the solution, we use the equation:
![pOH=-\log[OH^-]](https://tex.z-dn.net/?f=pOH%3D-%5Clog%5BOH%5E-%5D)
We are given:
![[OH^-]=5.09\times 10^{-5}M](https://tex.z-dn.net/?f=%5BOH%5E-%5D%3D5.09%5Ctimes%2010%5E%7B-5%7DM)
Putting values in above equation, we get:

To calculate pH of the solution, we use the equation:

Hence, the pH of the solution is 9.71
Answer: Combustion changes the potential chemical energy into kinetic energy in the form of heat. For combustion an organic wood combines with oxygen already in the air and undergoes a chemical reaction that gives off carbon dioxide,water,and energy in the form of heat and light.
HORMONES ARE CHEMICAL SUBSTANCES SECRETED BY GLANDS