Answer: (3) ppm
Explanation: Concentration is defined as the amount of solute dissolved in a known amount of the solvent or a solution.
Parts per million (ppm) is used to express the concentration when a very small quantity of solute is present in a large quantity of the solution. It is defined as the mass of solute present in one milion parts by mass of the solution.
L/s is used to express flow rate.
J/g is used to express energy per unit mass.
kPa is used to express pressure.
Answer:
Explanation:
When we are given Bohr models, we will be given a circle with rings surrounding it. The circle in the center of the model represents the nucleus, which contains the neutrons and the protons. The rings will have spherical structures that are attached to them in an orderly fashion - these model the electrons of an atom.
When we reference the model, we will see that there are 13 "p" and 14 "n" within the green circle. The "n" refers to <em>neutrons </em>and the "p" refers to <em>protons</em>. We can also count the red spheres and make quick observations about these: there are 2 red spheres on the innermost ring - for simplicity reasons, we will title this ring as r = 1. There are 8 red spheres on the middle ring - this ring will be titled r = 2. Finally, we can see that there are 2 more electrons in the outermost ring - this ring will be titled r = 3.
Now, because we have 13 protons, we know that the protons are equivalent to the atomic number.
Now that we have concluded that Aluminum is our element, we can check this to be sure. If we use the formula m = n + p (where m is the atomic mass, n is the neutrons, and p is the protons), we can check to be sure we have selected the right element.
The given mass of aluminum on the periodic table is 26.982 atomic mass units. We round to the nearest integer when it comes to this, so we round 26.982 up to 27 even.
Now that we have determined the atomic mass and we are given the number of both protons and neutrons, we can act as if we weren't given the amount of neutrons and only the mass and amount of protons. We can then use the equation to solve for the amount of neutrons and check that the selection we made is correct.
<u>Steps</u>
The work we just performed will allow us to confirm that because we solved for <u>14 neutrons</u>, Aluminum (Al) is indeed the element represented by the model.
Hope this helps! :)
