Answer:- The natural abundance of
is 0.478 or 47.8% and
is 0.522 or 52.2% .
Solution:- Average atomic mass of an element is calculated from the atomic masses of it's isotopes and their abundances using the formula:
Average atomic mass = mass of first isotope(abundance) + mass of second isotope(abundance)
We have been given with atomic masses for
and
as 150.919860 and 152.921243 amu, respectively. Average atomic mass of Eu is 151.964 amu.
Sum of natural abundances of isotopes of an element is always 1. If we assume the abundance of
as n then the abundance of
would be 1-n .
Let's plug in the values in the formula:

151.964=150.919860n+152.921243-152.921243n
on keeping similar terms on same side:


negative sign is on both sides so it is canceled:



The abundance of
is 0.478 which is 47.8%.
The abundance of
is = 
= 0.522 which is 52.2%
Hence, the natural abundance of
is 0.478 or 47.8% and
is 0.522 or 52.2% .
Answer:
Total of all numbers added with the correct rounding and number of significant figures
Explanation:
1. Add up all the numbers
8.32+8.00+8.30+8.3
2. Determine how many significant figures should be in your final answer. When it comes to addition, it will be the fewest number of decimal places. since 8.3 has one decimal place, your final answer should only have one decimal place.
3. Round your final answer to the nearest tenths
Answer:
no. of water molecules associated to each molecule of
= 4
Explanation:
Mass of
before heating = 19.8 g
Mass of
after heating = 12.6 g
Difference in mass of
before and after heating
= 19.8 - 12.6 = 7.2 g
Difference in mass corresponds to mass of water driven out.
Molar mass of water = 18 g/mol
No. of moles of water = 
Mass of
obtained after heating is mass of anhydrous
.
Mass of anhydrous
= 12.6 g
Molar mass of
= 125.9 g/mol
No. of mol of anhydrous
= 
so,
0.1 mol of
have 0.4 mol of water
1 mol of
will have = 
Hence, no. of water molecules associated to each molecule of
= 4
Answer:
Substances generate a smell when their molecules land on so-called olfactory neurones in our noses (which, for some things, is a pretty unpleasant thought). ... But this fails to explain why some molecules with similar shapes can smell completely different, while others with quite different shapes can have a similar scent.
Explanation:
I took chemistry
Answer:
pH + pOH = 14, [H₃0⁺] [0H⁻] = 10⁻¹⁴
Explanation:
When it comes to questions involving pH, the equations used are;
[H₃0⁺] [0H⁻] = 10⁻¹⁴
This equation shows the concentration of hydroxonium ions alongside that of the hydroxide ions.
pH + pOH = 14
If the value of either the pH of the pOH is know,one can calculate the value of the other using this equation.