This document discusses several key concepts in atomic structure and chemical bonding: Valence electrons are the outermost electrons of an atom that are involved in chemical bonding. The Aufbau principle states that electrons fill atomic orbitals in a specific order. Hund's rule explains that single electrons occupy each equal-energy orbital with the same spin before electrons pair up with opposite spins. Finally, the Pauli exclusion principle states that no two electrons can have the same set of quantum numbers, with a maximum of two electrons per orbital having opposite spins.

3. is the arrangement of electrons
within the orbitals of an atom to
determine its electronic property.

4. are the outermost electrons of an atom. They
are the highest energy electrons in an atom
and are the most reactive. Valence electrons
can be gained, lost, or shared to form
chemical bonds unlike the inner electrons
which do not participate in reactions.

5. The Aufbau Principle-the electrons in an
atom fill up its atomic orbitals according to
the Aufbau Principle; "Aufbau," in German,
means "building up." According to this
principle, electrons are filled in the following
order: 1s, 2s, 2p, 3s, 3p, 4s, 3d, 4p, 5s, 4d,
5p, 6s, 4f, 5d, 6p, 7s, 5f, 6d, 7p…

8. states that before additional electrons
with opposite spins can occupy the
same orbitals, single electrons with the
same spin must occupy each equal-
energy orbital first.

9. No two electrons can have the same
combination of four quantum
numbers. A maximum of two
electrons may occupy a single
orbital, but only if the electrons have
opposite spins.

15. 1. Why is it important to be aware of the
ingredients of the food you eat?
2. Based on your research, is your
favorite food good for your health? Why?
3. Why is it important to gain knowledge
on the properties and characteristics of
some elements?