In this video we are going to investigate what it means to put an atom’s, information into standard atomic notation. So first let’s. Just take a look at your average atom on the periodic table. Let’s. Look at fluorine, so there’s.
A whole bunch of information in the box for fluorine. So first thing is: we ‘ Ve got our name for fluorine, followed by a symbol of fluorine. Our atomic number for fluorine is 9. Now I want to point out that the atomic number represents the number of protons for each atom, so every atom on the periodic table has its own unique atomic number and, of course, that’s.
What the periodic table is arranged by atomic number from 1 to 118 and so forth. Next thing I’d, like to point out, is the average atomic mass of an atom? So, in this case, it’s, 18 point 9 9, and what we’re gonna do for our purposes today.
Is we’re going to round this number either up or down whatever’s convenient and it will be most convenient to round up to 19, which in fact is going to represent our mass number? Now the mass of an atom is the number of protons added together with the number of neutrons electrons are so light.
They’re, not considered to give any mass to an atom. Now the last piece of information in this box is going to be the charge of your atom and for fluorine it’s minus 1. So let’s. Take a look at what we need to do to create a standard atomic notation for an element.
First thing you’ll need is a symbol. Let’s use fluorine, so we know that fluorines atomic number is 9 from the previous slide. We also learned about the mass number, which is the protons plus the neutrons, which gives us 19.
So once it’s, sorted out that information, I should also point out that this atom has 9 protons there’s. No information leading me to believe that there’s a charge on this atom, so it must have the same number of electrons and if you want to figure out the neutrons, all we need to do is subtract 19, minus 9, giving us 10 neutrons.
So what happens if our example has a church? How does that affect the subatomic particles? Well, let’s. Take a look at fluorine and this time I’ve added a minus 1 charge to it. So what does that do for the subatomic particles? Well, fluorines number 9.
That means it’s, always going to have 9 proton. Now. What that minus one means is that we have an extra electron. We have one more electron than proton. So if we have nine protons, we have one more electron.
That must mean we have ten electrons and for us to figure out, the neutrons is still 19-9, giving us ten neutrons. So what if we have an example where we’ve got an overall positive value. All that means is that we have more protons than electrons, so calcium, which is number 20 on the periodic table, must have 20 protons.
So if we have more protons and we have tumour protons – that’s, what the plus 2 is of course indicating here, then we must simply have 18 electrons, so it’s, 20 positives 18 minuses that leaves us with an overall net Charge of +2 and lastly, figuring out the neutrons is once again 40 minus 20, giving us 20 neutrons.
Thank you very much.