00:01
So now we'll work on problem 16 from chapter 4.
00:07
This problem we're asked to determine the number of protons and neutrons for isotopes listed in a table, and we need to name each isotope and write its symbol.
00:18
So first we can produce the table here.
00:30
So first we have element.
00:36
We have from the table the atomic number.
00:43
And mass number.
00:51
We want to know the number of protons, number of electrons, number of neutrons, and then the name of the isotope, and its symbol.
01:14
So first we can start with the first element, which is calcium.
01:25
So we have calcium first.
01:50
After that, we'll work on oxygen.
01:58
Then we have iron, zinc, and mercury.
02:15
So calcium, the atomic number and mass number, which we are given, are 20 and 46.
02:26
So atomic number should equal to the number of protons and number of electrons.
02:31
We have 20 of those.
02:33
Number of neutrons will be the mass number minus the atomic number, so it's 26.
02:38
Since the mass number is the number of protons and neutrons combined...