Atomic Structure

Jamie Z 2024-01-29

Learning Goals

• Understand that atoms are modelled as a nucleus surrounded by electrons
• Use and apply the nuclear symbolic notation \(^A_ZM\)

Subatomic Particles - Protons, Neutrons and Electrons

Electron Shells

Electrons orbit in an Electron Shell. The Electrons are attracted to the protons but are repelled by the inner electron shells.

Atomic Mass and Electrical Charge

The atomic mass is determined by the sum of neutrons and protons

Subatomic Particle	Weight	Charge
Proton	1	+
Neutron	1	~
Electron	0	-

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Atomic Number

• Determined by the number of protons in each atom
• In an atom the number of protons = number of electrons

Notation of an Atom

• Atomic Mass = Protons + Neutrons
• Atomic Number = Number of Protons

Bhor Model

• First shell = 2 electrons
• Second Shell = 8 electrons
• Third shell = 8 electrons