00:01
Hello students, so for this video we have to fill up this chart.
00:05
So let's look at the first one.
00:08
In this symbol, the top one is the mass number and the bottom one is the atomic number.
00:14
So from this we can say that the mass number is 24 and the number of proton is equals to the atomic number that is equals to 12 and the number of electron is equals to the number of proton that is also equals to 12 and now number of neutron is equals to the mass number minus the atomic number that is 24 minus 12 that is 12.
00:46
Now for the second one we have the mass number 39 and the number of neutrons.
00:53
So the atomic number is equals to the mass number minus the number of 39 minus 20 that is 19 and the atomic number and the number of protons and electrons are equal and the symbol will be 19 and 39.
01:17
So the element with atomic number 19 is potassium.
01:23
Now let's look at the third one.
01:25
So in the third one we have the number of neutrons and the number of electrons.
01:29
So the number of electrons and protons are equal and that is also equals to the atomic number and now the mass number is actually the atomic number plus number of neutrons that is 26 plus 30 that is 56.
01:47
So the element is going to be 56 on top and 26 on bottom...