The two different isotopes have weights :
w1 = 78.918 amu
w2 = 80.916 amu
average weight w3 = 79.903 amu
The mixing of two components can be modeled as
let the fraction of w1 be 'x'
hence 
now this is a linear equation in 'x'. Substituting the values we get
x = 0.507
hence the percentage of Br79 = 50.7% and the percentage of BR81 = 49.3%
Answer:
Explanation:
For this case we have the following info given:
Number of Na+ ions 
Each ion have a charge of +e and the crage of the electron is 
The time is given 
if we convert this into seconds we got:
Now we can use the following formula given from the current passing thourhg a meter of nerve axon given by:
Where N represent the number of ions, e the charge of the electron and Q the total charge
If we replace on this case we have this:
And from the general definition of current we know that:
And since we know the total charge Q and the time we can replace:
The current during the inflow charge in the meter axon for this case is 
Answer:
You would need to type the numbers in the question or you could have added a picture but you didn't so there is no way to answer this question. Have a nice day!
There is an indirect relationship between length and frequency. The longer the length the pipe has, the higher frequency it is. The shorter the length the pipe has, the lower frequency it is.
<u>Explanation:</u>
The four properties of the string that affect its frequency are length, diameter, tension, and density. These properties are described below: When the length of a string is changed, it will vibrate with a different frequency. Shorter strings have higher frequency and therefore higher pitch.
The longer the tube is the lower the pitch of the note that it can emit. When a tube is heated it expands and so is longer! As the gas in the tube gets warmer the molecules move faster, that means they can carry the vibrations of the sound wave more rapidly and so the pitch goes up.
