Electrons are really lazy, they don't want to have alot of energy. And the closer they are to the nucleus (center) of an atom, the less energy they have to have.
So electrons live in orbitals that are around each atom. The bigger an atom is, the more orbitals it has.
Orbital are like little clouds that the electron can zoom around in. Orbitals that are close to the atom don't require the elecrons to have too much energy to live there, but orbitals that are farther away from the nucleus of the atom require electrons to have more energy to live there.
So why don't the electrons just all live in the closest orbital to the center of the atom (the nucleus)? Electrons have a negative charge, and they repel each other (just like me and my mother living in the same house). Electrons repel each other, so not a lot of them can hang out in the same orbital.
As a matter of fact, only two of them can be in the same orbital at any time. Scientists have given names to the orbitals, and also to the energy levels that those orbitals live in.
The energy level closest to the atom is called 1, and it has the lowest energy. But it is so small that it can only fit in one orbital for the electrons. That orbital is called the s orbital.
The next energy level up is called 2 (big surprise there), but it is big enough to hold an s orbital, and three p orbitals. p is an orbital that is shaped differently from an s orbital, that's all.
Each p orbital can only hold 2 electrons, just like an s orbital.
Let's recap. Level 1 only holds an s orbital - which means 2 electrons only.
Level 2 holds four orbitals - one s orbital, and three p orbitals - that means eight electrons.
As you might have guessed, there is another energy level, and it is called - you guessed it - 3!
Because level 3 is bigger than level 2, it can hold more orbitals, and so more electrons.
Level 3 has an s orbital, three p orbitals, and five d orbitals. Remember each orbital can hold two electrons. So level 3 can hold up to 18 electrons! (2 in the s orbital, 6 in the p orbitals, and 10 in the d orbitals).
Then, of course, there is a level 4. Level 4 has an s orbital, three p orbitals, five d orbitals, and seven f orbitals.
Hope this helps explain the basic idea!
So electrons live in orbitals that are around each atom. The bigger an atom is, the more orbitals it has.
Orbital are like little clouds that the electron can zoom around in. Orbitals that are close to the atom don't require the elecrons to have too much energy to live there, but orbitals that are farther away from the nucleus of the atom require electrons to have more energy to live there.
So why don't the electrons just all live in the closest orbital to the center of the atom (the nucleus)? Electrons have a negative charge, and they repel each other (just like me and my mother living in the same house). Electrons repel each other, so not a lot of them can hang out in the same orbital.
As a matter of fact, only two of them can be in the same orbital at any time. Scientists have given names to the orbitals, and also to the energy levels that those orbitals live in.
The energy level closest to the atom is called 1, and it has the lowest energy. But it is so small that it can only fit in one orbital for the electrons. That orbital is called the s orbital.
The next energy level up is called 2 (big surprise there), but it is big enough to hold an s orbital, and three p orbitals. p is an orbital that is shaped differently from an s orbital, that's all.
Each p orbital can only hold 2 electrons, just like an s orbital.
Let's recap. Level 1 only holds an s orbital - which means 2 electrons only.
Level 2 holds four orbitals - one s orbital, and three p orbitals - that means eight electrons.
As you might have guessed, there is another energy level, and it is called - you guessed it - 3!
Because level 3 is bigger than level 2, it can hold more orbitals, and so more electrons.
Level 3 has an s orbital, three p orbitals, and five d orbitals. Remember each orbital can hold two electrons. So level 3 can hold up to 18 electrons! (2 in the s orbital, 6 in the p orbitals, and 10 in the d orbitals).
Then, of course, there is a level 4. Level 4 has an s orbital, three p orbitals, five d orbitals, and seven f orbitals.
Hope this helps explain the basic idea!