Hey every one, will come the class for periodic table, today I'm going to have a activity of introducing each other. Also, we will go over some rules that will be needed in order to be a good element.
we can't wait to know each other!
I really want to learn some rules to be a good element
Hey my name is lithium and I have 1 electron in my outer most cell and I'm the third in the periodic table and the atomic mass of 6.9.
Hey my name is Boron, I have the atomic mass of 10.8 and I'm the 5th element in the periodic table.
Wait wait wait, why is this guy have a small radius but actually it is having a greater number of atomic mass?
This is because of the trends in atomic radius, it decreases from right to the left across the period, the reason of that is the electrons are added to the same energy level and the shielding are the same in a period. The increase of nucleus charge will pull the highest occupied energy close to the nucleus and the atomic size will decrease. Also you can see that electrons below you are much bigger than you, this is because the trends within groups are increasing because of the the positively charge could only attract the orbit closely to the nucleus but as the number of occupied energy level increases, it shields the attractions between the nucleus in the highest energy level, in other word, the shielding effect is greater than the attraction from the nucleus.
The noble gas element has the exception in the trend of radius because it has complete filled outer most shell and the reclusive force between the electrons make the atomic size bigger.
Why is my friend far away on the most right not follow the rule?