The Bohr Model of the AtomThe Bohr Model of the Atom

Topic #6Topic #6

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How can you identify an element How can you identify an element based on the number of electrons based on the number of electrons

and valence electrons?and valence electrons?

What do we know?What do we know?

Atoms have 2 main partsAtoms have 2 main parts

Electron cloud -- contains electronsElectron cloud -- contains electrons

Nucleus – contains protons and neutronsNucleus – contains protons and neutrons

Electrons = e-Electrons = e-

Protons = p+Protons = p+

Neutrons = nNeutrons = n00

What do you need to know?What do you need to know?

There are 7 possible orbitalsThere are 7 possible orbitalsYou can determine how many orbitals your You can determine how many orbitals your

model has by looking at what period (row) model has by looking at what period (row) the element is onthe element is on

The orbitals hold a specific number of The orbitals hold a specific number of electrons (which is the same as the atomic electrons (which is the same as the atomic number)number)

How many electrons per orbital?How many electrons per orbital?Period 1 Period 1 orbital (ring) 1: 2 e-orbital (ring) 1: 2 e-

Period 2 Period 2 orbital (ring) 1: 2 e-orbital (ring) 1: 2 e- orbital (ring) 2: 8 e-orbital (ring) 2: 8 e- Period 3 Period 3 orbital (ring) 1: 2 e-orbital (ring) 1: 2 e- orbital (ring) 2: 8 e-orbital (ring) 2: 8 e- orbital (ring) 3: 8 e-orbital (ring) 3: 8 e- Period 4 Period 4 orbital (ring) 1: 2 e-orbital (ring) 1: 2 e- orbital (ring) 2: 8 e-orbital (ring) 2: 8 e- orbital (ring) 3: 18 e-orbital (ring) 3: 18 e-

orbital (ring) 4: 8 e-orbital (ring) 4: 8 e-

Information to create a Bohr modelInformation to create a Bohr model

Element name and symbol: Element name and symbol: Magnesium (Mg)Magnesium (Mg)

Atomic number: 12Atomic number: 12 Mass number: 24Mass number: 24 Protons: 12Protons: 12 Electrons: 12Electrons: 12 Neutrons: (24 - 12) = 12Neutrons: (24 - 12) = 12

Bohr model for MgBohr model for Mg

12p+12n

Bohr model for AlBohr model for Al

13p+14n0

Draw the following Bohr models Draw the following Bohr models and Lewis Dot Structuresand Lewis Dot Structures

Boron Carbon Nitrogen Oxygen FluorineBoron Carbon Nitrogen Oxygen Fluorine

AluminumAluminum Silicon Phosphorus Sulfur ChlorineSilicon Phosphorus Sulfur Chlorine