00:01
The first nucleide or isotope that we have is yitrium 90.
00:07
Yitrium 90, if we go to the periodic table, yitrium has an atomic number of 39.
00:18
So we would write yitrium 39, and then 90 would be its mass number.
00:26
So the number of protons is equal to 39.
00:30
The number of neutrons is going to be its mass number minus its atomic number, which is going to give us 51, 51 plus 39 gives us 90.
00:52
So here's its chemical symbol.
00:53
There's its atomic number, its mass number, a number of protons, number of neutrons.
00:59
So the next one, we've got renium 186.
01:05
So we go to the periodic table.
01:07
And we look up renium.
01:13
Rhenium is r .e.
01:15
It has an atomic number of 75.
01:21
And if we have specifically renium 186, then its number of protons will be 75...