00:01
Hello, and in this question here we're going to investigate the density of the nukes.
00:05
So, to do this, we will first look at a lead atom.
00:11
Now, we write a lead atom as this, where this bottom number here refers to number of protons, and this top number here corresponds to number of nucleons.
00:35
And nucleons are protons and neutrons.
00:50
You might see that this top number here is represented by a and this number here is represented by z.
01:00
So first of all, to determine the net charge of the nucleus, so the nucleus is made up of protons and neutrons.
01:10
And here we see that it is 82 protons.
01:14
So protons have a positive charge.
01:29
And neutrons are neutral.
01:37
So the neutrons are going to contribute to the overall charge of the nucleus.
01:43
So the charge will only come from the protons.
01:47
Each proton contributes a plus one charge.
01:52
So the total charge charge is 82 times the charge of a neutron.
02:12
Sorry, of a proton.
02:18
Now, we know experimentally that the charge of a proton is equal to, so the charge q of a proton is equal to 1 .6 times 10 to the minus 19 of a cou.
02:30
So this means the total charge capital q is equal to 82 times the charge of a single proton, which is equal to 1 .32 times 10 to the minus 17 coulons.
02:49
Now to determine the number of neutrons, well, we have so a number of neutrons.
02:57
We have this top number up here, which is the number of protons and neutrons.
03:07
And this bottom number here is the number of protons.
03:10
So we simply subtract the top number from the bottom number.
03:13
So in this case, it will be 208 minus 82.
03:17
So 208 minus 82.
03:21
And that is equal to 126 neutrons.
03:26
Now, the top number above, so part c, the top number above, is, number of nucleons and number of nucleons and that is just given by the top number and that is equal to 208...