Isotopes - Video Tutorials & Practice Problems

Isotopes

isotopes are elements with the same number of protons, but different number of neutrons. Not with this whole idea. Lygia hopes we're gonna be introduced to some new terms. The first term is atomic number. Atomic number uses the variables e. It provides the number off protons. So basically, if I have an unknown element, But I know what's atomic number, I could go to the periodic table, look up that atomic number and will give me the identity off that unknown element. And because of this, we're going to say it helps us determine the identity and chemical properties of an element. The whole aspect of chemical properties of an element will discuss much later on in later chapters. Now, besides atomic number, we have mass number which is using the variable A. This one provides the number of protons and neutrons. Yeah, Now we're going to say, to calculate the number of neutrons, we can just take the mass number, which is a It's attracted by the atomic number, which is easy. That will tell us the number of neutrons for any given isotope or element. Now, if we take an atomic view of an atom, remember and um, Adam is composed off four primary parts. We have our nucleus, which houses the neutrons and protons, and we have our electrons which spin around the nucleus. Now, if we take a look here at this example, we know that our neutrons coated is red. If we take a look at this, Adam, we have 12345 and six for this particular atom protons, which we show us blue. We have in this example 12345 protons. The electrons are the green spheres that are rotating or orbiting the nucleus. We have electrons now remember, mass number, we said, is the number of protons, which is five plus the number of neutrons which, in this example, it's six. When you add those together, that gives us the mass number, which comes out to be 11. So I just remember you have blue and red mix together. It gives us the color purple. So we're using this Purple aid to designate are mass number for this particular atom. Now, we said earlier up above also that the atomic number gives us the number of protons. So if you know the number of protons. You know your atomic number in this example because we have five protons are atomic number has to be five. And because we know the atomic numbers five, we know the element identity here we don't show an example of a periodic table will go into greater discussion on it later on. But if we were to look at a periodic table, look for the atomic number five, we'd see that it belongs to the element off boron. So this Adam is an illustration of the element boron. And speaking of this, Adam, we're going to say for a neutral element, which is often times called an Adam, the number off protons and electrons are equal. And this makes sense because, remember, protons are positively charged. Electrons are negatively charged. If you have equal numbers of positive and negative, they're going to cancel one another out and you'll be left with a neutral element. So just remember when we're dealing with the neutral element, that's another way of saying Adam in Adam, the number of protons and electrons are equal Now, later on, we'll talk about other species called ions in ions. The number of protons and electrons are not equal okay, But for right now, just realize that they're doing the word neutral words neutral element or Adam. We're dealing with a species or an element that has the same number of protons and electrons. Now that we've looked at the atomic view of the atom. Now that we've incorporated these new terms of mass number and atomic number, let's continue our discussion exploration of the atom itself.

Isotopes Example 1

all right, so we've discussed isotopes being elements that have the same number of protons but different number of neutrons. The way we represent these isotopes is through what we call isotope notation. Now this is just the representation for an isotope, and it includes its atomic number, which, remember, is Z. It's mass number, which is a and now it's elements Symbol X. Remember, our periodic table of the elements has the display of all the elements that we know off with their elemental symbols. For example, carbon is represented by the elements symbol seat in this example. Down below we have calcium, which is represented by C A. Typically, when we talk about isotope notation, we have our mass number presented here on top on the bottom. We typically have our atomic number Z on the bottom and then the symbol for the element here. So if we take a look at this question, it's telling us that we have calcium 43 it represents one of the isotopes for the calcium Adam. If the number 43 represents its mass number, determine the correct numbers for it's a subatomic particles. All right, so we're gonna say calcium 43 again, I say. Within the example, Question 43 represents its mass number, which is this number right here. Here. It's mass numbers 43 Its atomic number is 20. And the elements symbolist see a representing calcium. All right, remember that the atomic number Z is equal to the number of protons here. The atomic number is 20. So that means we have 20 protons. So that means our answer at this point can either be a or D. So be in Sierra next. Let's determine the number off neutrons because that's the next subatomic particle that shown we're going to say here that remember, up above we said the number of neutrons equals your mass number, which is a minus your atomic number, which is Z. So if we look at this isotopic symbol for calcium, we see that the mass number is minus Okay, 20. So that's gonna give us 23 neutrons. So we have 23 neutrons. A says we have 43 neutrons. We know that cannot be the answer. So it looks like D is the correct choice, not let's talk about the number of electrons. How do we determine the number of electrons? Well, they say the word Adam within the question. Remember, we're talking about the word, Adam. We're dealing with the neutral element for neutral element. The number of electrons equals the number of protons. So since my number of protons is 20 my number of electrons also must be 20. So the answer here would be D Now, remember, with Adams, we're dealing with neutral elements. Number of protons and electrons are equal. If they had said the word ion, then with the word ion, that would mean that the number of electrons and protons would be different. We haven't quite gotten there, but just remember that we're eventually gonna get to a point where the number of electrons and protons will not be the same. In those cases, we will no longer have a neutral element. It will have a charge. Okay, but for this example, because we're dealing with Adam, let's just focus on the fact that we have the same number of protons and electrons

Which of the following answers give the correct number of subatomic particles for ?

• A. 38 protons, 38 neutrons and 38 electrons
• B. 88 protons, 50 neutrons and 50 electrons
• C. 38 protons, 50 neutrons and 38 electrons
• D. 38 protons, 27 neutrons and 13 electrons

Which of the following answers give the correct number of subatomic particles for ?

• A. 34 protons, 34 neutrons and 34 electrons
• B. 50 protons, 18 neutrons and 18 electrons
• C. 16 protons, 18 neutrons and 16 electrons
• D. 17 protons, 17 neutrons and 17 electrons