A chemical or physical change
I would say it should be Einstein's famous equation of e=mc^2 which means energy =mass x the speed of light squared. With this equation Einstein showed that energy comes from a mass travelling at the speed of light squared which is a fundamental equation to explain physical phenomena.
Answer:At the molecular level, the pressure of a gas depends on the number of collisions its molecules have with the walls of the container. If the pressure on the piston is doubled, the volume of the gas decreases by one-half. The gas molecules, now confined in a smaller volume, collide with the walls of the container twice as often and their pressure once again equals that of the piston.
Explanation:
<u>Answer:</u> The percentage abundance of 
and 
isotopes are 77.5% and 22.5% respectively.
<u>Explanation:</u>
Average atomic mass of an element is defined as the sum of masses of each isotope each multiplied by their natural fractional abundance.
Formula used to calculate average atomic mass follows:
.....(1)
Let the fractional abundance of isotope be 'x'. So, fractional abundance of isotope will be '1 - x'
- <u>For isotope:</u>
Mass of isotope = 35 amu
Fractional abundance of isotope = x
- <u>For isotope:</u>
Mass of isotope = 37 amu
Fractional abundance of isotope = 1 - x
Average atomic mass of chlorine = 35.45 amu
Putting values in equation 1, we get:
![35.45=[(35\times x)+(37\times (1-x))]\\\\x=0.775](https://tex.z-dn.net/?f=35.45%3D%5B%2835%5Ctimes%20x%29%2B%2837%5Ctimes%20%281-x%29%29%5D%5C%5C%5C%5Cx%3D0.775)
Percentage abundance of isotope = 
Percentage abundance of isotope = 
Hence, the percentage abundance of and isotopes are 77.5% and 22.5% respectively.
