The Bohr Model of the Atom

What do we need to know? Atoms have 2 main parts Electron cloud -- contains electrons Nucleus – central part of the atom, contains protons and neutrons

Subatomic particles Symbols for each subatomic particle Electrons = e- Protons = p+ Neutrons = n0

What do you need to know? Orbitals are found around the nucleus There are 7 possible orbitals Orbitals are determined by by looking at what period (row) the element is in The orbitals hold a specific number of electrons (which is the same as the atomic number)

How many electrons per orbital? Period 1  orbital (ring) 1: 2 e- Period 2  orbital (ring) 1: 2 e- orbital (ring) 2: 8 e- Period 3  orbital (ring) 1: 2 e- orbital (ring) 3: 8 e- Period 4  orbital (ring) 1: 2 e- orbital (ring) 3: 18 e- orbital (ring) 4: 8 e-

Information to create a Bohr model Atomic # = Protons and Electrons Element name and symbol: Magnesium (Mg) Atomic number: 12 Atomic mass: 24 Protons: 12 Electrons: 12 Neutrons: (24 - 12) = 12 12 Mg 24.305 Magnesium Atomic Mass

Bohr model for Mg Nucleus 12p+ 12n0

Bohr model for Al 13p+ 14n0 Ask “How many orbitals should Al have?”; “How many protons?”; “How many neutrons?”; “How many electrons in the first orbital?”; “How many electrons in the second orbital?”; “How many electrons in the third orbital?”; “What is so special about these 3 electrons?”

Questions??