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Name:____________________ Period:________ Ch5 Notes (contd.) Date: 11-20-2018

Review of previous notes: There are at least 7 Principal energy levels known for each atom. They are also referred to as energy levels (n) are also called ___________. n=1 has the lowest energy and is located ___________ to the nucleus. As energy levels move farther away from the nucleus, their energy increases. The table below shows the different sublevels that are contained with in each specific principal energy level. Sublevels are just a group of similar shaped orbitals. Energy level n=1 has __________ one s-subshell and n=2 has two subshells, ___ and ___. n=2 has 3 subshells: s, p and d. From n=4 up to n=7, all have ___ subshells: s, p, d and f.

The number of orbitals in each sublevels are shown in the table below: The s-subshell s has __ orbital, p-subshell has ___ orbitals while d and f subshells have 5 and ____ orbitals respectively. Since each orbital can have a maximum of 2 electrons, the s subshells with a single orbital can have a maximum of ___ electrons while p can have ___, d can have ___ and f has a total of 14 electrons. Ex. Hydrogen has a single electron that is located in the 1s orbital located in n=1. Electrons find homes in orbitals there is a specific filling order going from lowest to highest energy.

Electron configuration (filling order):

The home addresses (LOCATIONS) of all the electrons in an atom are called the electron configuration. There are two ways of writing electron locations:

1. Configuration 2. Orbital diagrams (arrow and box diagrams)

If an orbital has two electrons they are called an electron pair. If an orbital has a single electron it is called an unpaired electron. In the diagram below, the 3p sublevel has two paired electrons and one unpaired electron. Using the figure below write the electron configuration starting at 1s and ending at 4s. Add the total number of electrons in each sublevel as a superscript as shown in the diagram inside the box below: 1s2 ___________________________________________________________________________________

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Examples of orbital (box) diagrams:

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Guided practice question: Q1: Write the electrons configuration, box and arrow diagram for an atom with 32 protons. What is the numbber of electrons in its valence shell (highest energy level)? What is the connection between the group number and the valence electrons? What is theis element called?

STEPS for writing electron configurations of given atoms: a. Find the total number of electrons: 38 (number of protons = number of electrons)

b. Determine the electron filling order =CONFIGURATION: 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2

c. Box and arrow diagram:

d. The number of electrons in valence shell: 2 (5s2 : n=5 is the highest energy level)

e. Group number: 2A or 2

f. Element: Strontium (Sr)

Questions: 1. You can tell the total number of electrons in a electron configuration by counting the total number of __________ _______________________ .

2. The total number of electrons in: 1s2 2s2 2p6 3s2 3p6 is ________. The number of valence electrons is:______. Valence shell electron configuration is:____________. 3. Write the electrons configuration, box and arrow diagram for an atom with 17 protons. What is the numbber of electrons in its valence shell (highest energy level)? What is the connection between the group number and the valence electrons? What is theis element called?

STEPS a. Find the total number of electrons:

b. Electron configuration: ______________________________________________________

c. Box and arrow diagram: ______________________________________________________________

d. The number of electrons in valence shell: ________

e. Group number: _________

f. Element: Strontium (Sr):__________

4. The number of electrons in the atoms indicated by an arrow on the Cards: Groups (a) group-1:________ (b) group-4:________ (c) group-7:________ (d) group 8:________ 5. he group number of elements is connected with the electrons in the _____________ _____________.

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Name:____________________ Period:____ Home work 8: Due: 11-26-18 ( /100 points)

8. write the electron configurations of:

a. 12 Mg:______________________________________________________________

b: 39Y: ______________________________________________________________

c. 8 O: ______________________________________________________________

9. Write the Orbital diagrams of:

a. 12 Mg: ______________________________________________________________

b: 39Y: ______________________________________________________________

c. 8 O: ______________________________________________________________