The document discusses electron configuration and the evolution of atomic models, detailing Niels Bohr's planetary model and the quantum mechanical model introduced by Erwin Schrödinger. It highlights key principles such as Heisenberg's uncertainty principle and de Broglie's wave behavior of electrons, along with Hund's rule for electron filling in orbitals. Additionally, it explains the capacity of different sublevels in terms of electron accommodation.

1. LECTURE 2.1
Electron Configuration
2nd
Quarter
Grade 9

3. Planetary Model
Niels Bohr
Stated that electrons
moved around the nucleus
in orbits of fixed sizes and
energy

6. •Werner Karl Heisenberg,
“Uncertainty Principle,” states that
we can only conclude the electron’s
probable location outside the
nucleus but not the exact location.
•Louie de Broglie explains that
electrons could also be taught to
behave like a wave.

7. Quantum Mechanical Model
Erwin Schrodinger
Stated that electrons do
not move around the
nucleus, but in waves.

9. Quantum Mechanical Model
It is impossible to know
the exact location of the
electrons; instead, there
are “clouds of probability”
called orbitals.

12. Electron Configuration
The electron configuration
of an element describes
how electrons are
distributed in its atomic
orbitals.

13. 2 6 10 14

15. •Always remember that:
s sublevel can handle 2 electrons,
p sublevel can handle up to 6
electrons,
d sublevel can handle up to 10
electrons
f sublevel can handle up to 14
electrons.

16. Hund’s Rule
This rule describes the
order in which electrons
are filled in all the orbitals
belonging to a subshell.

17. Hund’s Rule
It states that every orbital
in a given subshell is singly
occupied by electrons
before a second electron is
filled in an orbital.

18. Hund’s Rule