The average mass of an atom is calculated with the formula:
average mass = abundance of isotope (1) × mass of isotope (1) + abundance of isotope (2) × mass of isotope (2) + ... an so on
For the boron we have two isotopes, so the formula will become:
average mass of boron = abundance of isotope (1) × mass of isotope (1) + abundance of isotope (2) × mass of isotope (2)
We plug in the values:
10.81 = 0.1980 × 10.012938 + 0.8020 × mass of isotope (2)
10.81 = 1.98 + 0.8020 × mass of isotope (2)
10.81 - 1.98 = 0.8020 × mass of isotope (2)
8.83 = 0.8020 × mass of isotope (2)
mass of isotope (2) = 8.83 / 0.8020
mass of isotope (2) = 11.009975
mass of isotope (1) = 10.012938 (given by the question)
Answer:
The arguments both for and against allowing genetically altered meats into the United States is explained below in details.
Explanation:
Arguments for and against genetically altered meats:
- Supply the Society. By 2050, the world's inhabitants are supposed to increase from today's 7 billion to way beyond 9 billion.
- ENVIRONMENTAL RISK.
- STRONGER CROPS = LESS PESTICIDES.
- REMEMBER WHEN CIGARETTES WERE 'HARMLESS'?
- TAMPERING FOR TASTE. ...
- BIG BUSINESS EATS SMALL FARMERS.
- ENHANCED HEALTH.
- NOTHING TASTES BETTER THAN NATURE.
Answer:
760 uM
Explanation:
<em>A biochemist carefully measures the molarity of magnesium ion in 47, mL of cell growth medium to be 97 uM. Unfortunately, a careless graduate student forgets to cover the container of growth medium and a substantial amount of the solvent evaporates. The volume of the cell growth medium falls to 6.0 mL. Calculate the new molarity of magnesium ion in the cell growth medium Be sure your answer has the correct number of significant digits.</em>
The problem here is that the amount of magnesium ion remains the same irrespective of the volume.
Amount of magnesium in the growth medium = <em>molarity x volume</em>
= 97 x 
x 47 x 
= 4.559 x
Then, the volume reduced to 6.0 mL, the new molarity becomes;
<em>molarity = mole/volume </em>
= 4.559 x /6 x = 7.598333 x 
M = 759.83333 uM
To the correct number of significant digits = 760 uM
Answer:
Because if you use pen, your chromatography will separate also the colors of the pen and not just your sample.
Explanation:
The pencil since is carbon as simple element, is solid and is not dissolved in solvents like commonly are used in paper chromatography, it will not interrupt the separation of the compounds in your mixture, otherwise, your results will be confuse because you are not sure if the spots that you observe is due to the ink pen or due to the mixture that you want to separate.
