00:01
Okay, we need to give the number of protons, neutrons, and electrons, and the following isotopes.
00:08
And at the end, we need to name elements a, b, c, and d.
00:14
So i will give the names for a, b, c, and d as we go through.
00:17
So first one, atomic number is nine.
00:30
What is atomic number? by the way, atomic number is literally the number of protons.
00:36
That's how atomic number is defined.
00:38
Every element is defined by the number of protons.
00:41
It has hydrogen has one proton.
00:43
Helium has two.
00:44
There can be various isotopes of those elements.
00:48
But once you change the number of protons, in fact, you change the element itself.
00:55
Therefore, for each of these, they're going to tell us the atomic number, and we know right away that that means that it's protons, right? so i'll just say a9 protons.
01:12
Next, they're telling us the mass number equals 18.
01:21
What is the mass number? the mass number is equal to neutrons plus protons.
01:31
We know there's nine protons.
01:33
The mass number is 18.
01:35
We do a little bit of algebra or just say, well, 9 plus 9 equals 18.
01:40
We have 9 neutrons.
01:45
And finally, they tell us the charge equals negative one.
01:51
What's the formula for charge? well, it's protons minus electrons, right? so we could solve for electrons, essentially.
02:05
Or we know that protons minus electrons equals negative one means we have one more electron than we do protons.
02:11
Either way, we're going to get 10 electrons.
02:15
Okay.
02:18
Also, i'm going to move to moving p plus.
02:19
For proton and zero for neutron and e minus for electron okay uh next thing right we have to give the element what is atomic element number nine should be nitrogen let's get a periodic table nope it's fluorine look at me don't i feel silly right nine that's fluorine okay next b the atomic number equals 43 hey, we already said that's literally just the number of protons.
03:10
43 protons.
03:14
That one's pretty simple...