1. A New Model By 1925, Bohr’s model was in need of some remodeling
With some new information, other scientists proposed a model where electrons behaved more like waves on a vibrating string than particles circling the nucleus in an orderly fashion e- e- e-

2. Today, electrons are nearly impossible to exactly pinpoint in an atom because they move so fast
Think of how fast the blades of a fan rotate- can you pick out just one?
Therefore, all scientists can do is predict the location of an electron at any given moment, and use shading to do so
The darker the shading, the more likely it is to find an electron- the shaded region is called and electron cloud

3. Where are Electrons Most Likely to be Found?

4. Electrons are found in regions called orbitals
An orbital is an area of an atom where there is a high chance of finding an electron
There are 4 types of orbitals: s, p, d, and f

5. s orbital
The s orbital is the simplest one- it is shaped like a sphere and surrounds the nucleus
It can hold a maximum of 2 electrons
This is the lowest-energy orbital

6. p orbital
The p orbital is a little more complex, and has 3 dumbbell-shaped regions that surround the nucleus
Each dumbbell region can hold 2 electrons- with 3 regions, that’s 6 total electrons that can fit in the p orbital
This orbital has a
little more energy than
the s orbital

7. d and f orbitals
The d orbital is made of 5 regions- if each area holds 2 electrons, how many total electrons can fit in the d orbital?
The f orbital is the most complex, and is made of 7 regions- each can hold 2 electrons for a total of 14 electrons in the f orbital
d has more energy than
the p orbital, and f has
the most energy of the 4

8. Electrons always fill the s orbital first, then p, d, and lastly f
This is in order of energy! Remember: the s orbital has the least amount of energy, and f has the most

9. Valence Electrons
The outermost electrons of an atom are called the valence electrons
These electrons are found in the energy level furthest from the nucleus

10. Lab Day- Electron Orbital Activity