Answer:
The concentration of this solution in units of pounds per gallon is 
Explanation:
Units of measurement are established models for measuring different quantities. The conversion of units is the transformation of a quantity, expressed in a certain unit of measure, into an equivalent one, which may or may not be of the same system of units.
In this case, the conversion of units is carried out knowing that 1 μg are equal to 2.205*10⁻⁹ Lb and 1 mL equals 0.00022 Gallons. So

If 1 μg equals 2.205*10⁻⁹ lb, 2.77 μg how many lb equals?

lb=6.10785*10⁻⁹
So, 2.77 μg= 6.10785*10⁻⁹ lb
Then:

You get:

<u><em>The concentration of this solution in units of pounds per gallon is </em></u>
<u><em></em></u>
In Chemistry, to better determine the position of a certain electron, quantum numbers are used. The four quantum numbers are n, l, m and s. In the given above of n= 4, the principal quantum number is 4 and this represents the overall relative energy in the orbital. This means that we are to find the maximum number of electrons in fourth main energy level and the answer is 32.
Answer:(I didn’t really know where to Wrigh-)
Explanation: Gas bubbles appear after a chemical reaction has occurred and the mixture becomes saturated with gas. The chemical change that creates the gas is completed after the gas bubbles leave the mixture.
Answer is: A. They opposed the use of energy released during nuclear fission for military purposes.
Hahn, Strassmann and Meitner were not engaged in nuclear weapons research during World War II.
Otto Hahn (1879 - 1968) became a passionate campaigner against the use of nuclear energy as a weapon.
Hahn and Strassmann discovered nuclear fission (nuclear fission of uranium in 1939).