You take 80 g of Neon times 1 mol over the molar mass, 20.18 g/mol and multiply by Avogadro's number.
True. Any cosmetic containing paraffin wax, benzene, mineral oil, PEG, DEA, MEA, the suffix ethyl- or propyl-, etc. About 95% of fragrances contain petrochemicals.
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% .
Maybe it’s c I’m not sure
The answers include:
- A loaf of risen but unbaked bread - chemical change.
- Photo by Elinor D - chemical change.
- Bread dough rising - chemical change.
<h3>What is a Chemical change?</h3>
This involves the formation of a new products from substances. In this scenario, a rising bread contains alcohol which evaporates.
Photographs also fall under this category and is therefore an irreversible chemical change.
Read more about Chemical change here
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