What is an Ion?

In this video we are going to talk about ions,

what

exactly is an ion? A good example that Alex used is the aluminum ion. Aluminum has an atomic number of 13 and a mass number of 27, let's compare it with an aluminum atom, etc. On the left side we have the ion and on the right side the atom. As you can see, an ion has an electric charge. An atom is neutral. There is no charge. The question is why atoms are neutral, but why do ions have a positive charge or a negative charge? an ion with a positive charge is known as a cation an ion with a negative charge is known as an anion the atomic number is equal to the number of protons so the aluminum atom and the aluminum cation have 13 protons however, an ion is different from an atom based on a number of electrons to calculate the number of electrons is equal to the atomic number minus the charge, so in the case of the atom 13 minus a charge of zero is 13 for the ion, it will be 13 minus a positive charge3 So 13 minus 3 is 10, so the aluminum ion has 10 electrons.

As you can see, the reason why an atom is electrically neutral is because the number of protons and electrons is the same, but in an ion the number of protons and electrons is different and that is why there is a net charge, each proton has a positive charge and an electron has a negative charge, so if you add the charges of the ion you have a charge of posi3 in the nucleus and in the electron cloud -10 if you add those numbers you will get the net charge of the ion if you do the Same for the atom, you have 13 protons, that's the charge of 13 13 positive electrons, so it's a charge of 133, the net charge is zero and that's why there's nothing on top of it here, so the atom It is electrically neutral, so ions are differentiated from atoms according to the number of electrons.

As long as you have a substance with the same number of protons and electrons, it is neutral when the protons and electrons are different, the substance will be charged and in the case of an atom, it becomes an ion when they have different numbers of protons and electrons. . Now let's look at another example. Let's use phosphorus. Actually, let's choose a different element. Let's use sulfur. Sulfur has an atomic number of 16. Its mass number is usually 32. so here we are going to have the ion and on the left the atom how many protons and electrons are there in these two particles the number of protons is equal to the atomic number so both particles contain 16 protons in an atom the number of protons and electrons will always be the same in the ion.

You can calculate this by taking the atomic number 16 and subtracting it by the net charge, so 16 - -2 is the same as 16 + 2, which is 18 whenever you have a negatively charged anion. The number of electrons will be greater than the number of protons and that is why the net charge is negative. In the case of the last example where we had a positively charged cation, there were more protons than electrons and that is why the overall charge was positive, so for this particular ion we have 16 protons with a net charge of 16 and 18 positive electrons. If we add these two numbers together, this will give us the net charge of the ion which is -2, so keep in mind that ions have a different number of protons and electrons.

But atoms have the same number of protons and electrons. Now let's work on some problems. Write the atomic symbol for each ion. So let's say if you are given the number of protons, neutrons and electrons, how can we write the atomic symbol? So feel free to pause the video and try this problem if you want, so let's say if we have some element X, we have the atomic number Z, the mass number, you can call it m or a. I'll call it m for mass and then the charge. Let's say the charge is c z is always equal to the number of protons that is the atomic number the mass number is the sum of the protons and neutrons the charge is the difference between the protons and the electrons the negative sign has to do with the fact that the electrons are negatively charged, so it is not necessary to put another negative sign in this equation, so for part A the number of protons is 15, therefore Z is 15, the number of neutrons is 16, so

what

the mass number will be the protons. plus the neutrons, then there are 15 + 16, which is 31.

Now the charge will be the difference between the protons and the electrons. So it's 15 - 18, so we're going to have a net charge of 3 because there are more electrons than protons. we have a negatively charged anion so now we have element x with an atomic number 15, a mass number of 31 and a charge of 3. Now the last thing we need to do is identify element element you need to use the prct table and you can identify it based on the atomic number or the number of protons, so which element has an atomic number of 15? If you look at the periodic table, there will be two numbers that You will see that the atomic number is always the smaller of the two numbers, so phosphorus has an atomic number of 15, so this is the atomic symbol, it is 1531 pus 3, This is how you can write the atomic symbol for an ion.

Go ahead and try Part B Z, which is the number of protons is 26 the mass number will be the protons plus the neutrons so 26 + 30 and that's 56 finally we need to calculate the charge which is the protons minus the electrons so 26 minus 23 that is POS 3 so because there are more protons than electrons, that charge is positive, so we have a positively charged cation, so we got an atomic number of 26, a mass number of 56 and a charge of position 3. The last thing What we should do is identify the element, so what element has an atomic number of 26? If you look at the periodic table, it's Fe.

Okay, this is the ionic symbol for Fe. Now you know how to write it if you're given the number of protons, neutrons and electrons, so here's another practice. problem for you what is the net charge of an ion with 29 protons 34 neutrons and 27 electrons to find the net charge all you need to do is take the difference between the number of protons and electrons so we have 27 protons and 27 I want say, 29 protons, I take that back, but 27 electrons, so 29 - 27 is pos2, so we have a positively charged cation, since there are more protons than electrons, so here's another problem you could try: How many electrons does an ion have with 32 protons and the net?

The charge of pos4 has so let's start with an equation to calculate the number of electrons, we know that it is equal to the atomic number minus the charge and the atomic number is basically equal to the number of protons that we already have, so in this example there are 32. protons and the charge is pos4, so it is 32-4, so it is 28 and since the charge is positive, there will be less electrons than protons and that is the answer, so you have 32 protons and a charge of pos4, you only have 32 - 4 and get 28, that will be four electrons less than protons if the charge is more4, so that's it for this video and thanks for watching.