Africa is the answer. Here is the packet, https://cms.springbranchisd.com/Portals/280/staff/robertsh1/exptra%20practice%20KEY.pdf?ver=2012-11-...
<span>The smallest unit of an element that retains all the characteristics of that element is called an A. atom.
Atoms consist of protons, electrons, and neutrons, but they are particles and don't have the characteristics of the element which is why D is incorrect. B and C are not the smallest units - atoms are smaller than them.
</span>
K is Potassium
Cl is Chlorine
There are 2 elements.
We know that to relate solutions of with the factors of molarity and volume, we can use the equation:

**
NOTE: The volume as indicated in this question is defined in L, not mL, so that conversion must be made. However it is 1000 mL = 1 L.
So now we can assign values to these variables. Let us say that the 18 M

is the left side of the equation. Then we have:

We can then solve for

:

and

or

We now know that the total amount of volume of the 4.35 M solution will be
210 mL. This is assuming that the entirety of the 50 mL of 18 M is used and the rest (160 mL) of water is then added.