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>
Answer:
B-Sucrose molecules are too large to conduct electricity in once dissolved in water.
D-Salts, like NaCL, have ionic bonds and are considered to be electrolytes:when dissolved in water, salts dissociate and form ions.
Explanation:
Answer: The rate constant for the reaction is 
Explanation:
Expression for rate law for first order kinetics is given by:

where,
k = rate constant
t = age of sample = 559 min
a = let initial amount of the reactant = 
a - x = amount left after decay process = 



The rate constant for the reaction is 
Second- Beryllium (Be)
Third- Magnesium (Mg)
Fourth- Calcium (Ca)
Fifth- Strontium (Sr)
Did you mean significant figures? If so, 67.6(1.2)=81
When multiplying, you always leave the the answer in the least amount of significant figures.