Answer:
The percentage abundance of Eu isotopes are 52 % and 48 %
.
Explanation:
The formula for the calculation of the average atomic mass is:
Given that:
Since the element has only 2 isotopes, so the let the percentage of first be x and the second is 100 -x.
For first isotope,:
% = x %
Mass = 151.0 amu
For second isotope :
% = 100 - x
Mass = 153.0 amu
Given, Average Mass = 151.96 amu
Thus,
Solving for x, we get that:
x = 52 %
<u>Thus percentage abundance of Eu isotopes are 52 % and 48 %
.</u>
C is the answer hope the answer is right
Answer : The ions present in the solution of
are
and
in aqueous state.
Explanation :
When
is in aqueous solution then they dissociates into their ions.
The reaction in aqueous medium is,

The charge on potassium ion is +1 and on carbonate ion is -2. To neutralize the charge on carbonate ion, two potassium ion must be used.
Therefore, the ions present in solution of
are
and [tex]CO^{2-}_3[tex] in aqueous state.
Answer:
249.94ppm
Explanation:
Given parameters:
Mass of Pb(NO₃)₂ = 0.025g
Mass of water = 100g
Unknown:
Concentration of solution in ppm = ?
Solution:
Concentration in parts per million gives the amount of solute found in a million units of the solution. They are desirable for expressing very small amount of solutes in a large solution. For example, the level of arsenic in the soil.
Concentration in ppm = 
A solution is made up of solute and solvent. The solvent here is water.
mass of solution = mass of solute + mass of solvent = 0.025 + 100 = 100.025g
Concentration in ppm =
= 249.94ppm