Answer:
a.) 22.4 L Ne.
Explanation:
It is known that every 1.0 mol of any gas occupies 22.4 L.
For the options:
<em>It represents </em><em>1.0 mol of Ne.</em>
<em />
using cross multiplication:
1.0 mol occupies → 22.4 L.
??? mol occupies → 20 L.
The no. of moles of (20 L) Ar = (1.0 mol)(20 L)/(22.4 L) = 0.8929 mol.
using cross multiplication:
1.0 mol occupies → 22.4 L.
??? mol occupies → 2.24 L.
<em>The no. of moles of (2.24 L) Xe </em>= (1.0 mol)(2.24 L)/(22.4 L) = <em>0.1 mol.</em>
- So, the gas that has the largest number of moles at STP is: a.) 22.4 L Ne.
Ln(800/3200) = - kt
t = 24 years.
ln(0.25) = -k*24
(- 1.3863) = -k*24
1.3863 / 24 = k
0.05776 = k
ln(0.5) = -k*t
-0.6931 = - 0.05776 t
12 = t
I don't know if you can just look at the question and know the answer. If 24 years is a quarter life then is it obvious that the 1/2 life is 12 years? It might be, but the method I've used works for sure.
Answer:
4.427 × 10⁵
Explanation:
In mathematics, rounding up a number is a way to get a more simpler figure but not too distant from the original number. Rounding up a whole number like this (442722) to significant figures means having only four non-zero digits in the figure i.e. 442722 ~ 442700.
This means that 442722 has been rounded up to 4s.f. Hence, to use scientific notations to represent our answer, we count the number of decimal places from right to left i.e.
442700 = 5 decimal places if the point is between 4 and 4 i.e. 4.427
Therefore, the figure 442700 can be written as 4.427 × 10⁵ using scientific notation.
Answer:
Salt is a compound
Explanation:
Pure salt consists of the elements sodium and chlorine. Its chemical name is sodium chloride and its formula is NaCl. ... Table salt is a chemically simple combination of two components, sodium and chlorine.
I'm guessing its Sublimation point of water
Hope this helps
