Pretend you are a teacher preparing a quiz for the text I will provide. 
            Each quiz question should follow the format below. 
            Ensure that you carefully recheck the questions and answers for accuracy. 
            The output should be a ready-to-use list of dictionaries for the Python eval function:

            [

                    "question": "WRITE THE QUESTION HERE",
                    "options": ["A) OPTION_1", "B) OPTION_2", "C) OPTION_3", "D) OPTION_4"],
                    "answer": INDEX_OF_CORRECT_ANSWER_IN_OPTIONS_LIST,
                    "explanation": "EXPLAIN WHY THE ANSWER IS CORRECT"

            ]

            Text:
             structures and 
reactions
– Includes biological molecules, drugs, solvents, dyes
– Does not include metal salts and materials (inorganic)
Dr. Ayman Amrat   1
Essential oils
Materials
Fuels
Pigments
Medicines
Some organic chemicals
Atomic Structure
Structure of an atom
- Positively charged nucleus (very dense, 
protons and neutrons, and small (10-15 m)
- Negatively charged electrons are in a cloud 
(10-10 m) around nucleus
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Atomic Number and Atomic Mass
- The atomic number (Z) is the number of protons in the 
atom's nucleus.                                                                      
All atoms of a given element have the same atomic 
number.
- The mass number (A) is the number of protons plus 
neutrons.
The atomic mass (atomic weight) of an element is the 
weighted average mass in atomic mass units (amu) of an 
element’s naturally occurring isotopes
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Isotopes are atoms of the same element that  
have different numbers of neutrons and 
different mass numbers
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Atomic Structure: Orbitals
• Four different kinds of orbitals for electrons based on 
those derived for a hydrogen atom: s, p, d, and f
• s and p orbitals most important in organic chemistry
• s orbitals: spherical, nucleus at center
• p orbitals: dumbbell-shaped, nucleus at middle
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Numbers of Orbitals and electrons in the First 
Three Shells
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Atomic Structure: Electron Configurations
• Ground-state electron configuration of an 
atom lists orbitals occupied by its electrons.
• Rules:
1. Lowest-energy orbitals fill first:                          
1s 2s 2p 3s 3p 4s 3d
2. Electron spin have only two orientations: 
up and down . 
3. Only two electrons can occupy an orbital, 
and they must be of opposite spin
Dr. Ayman Amrat   7
Electron Arrangements of the First 18 elements
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CHEMICAL BONDS: THE OCTET RULE
Why do atoms bond together?
Lewis proposed that an atom is most stable if its outer shell is filled 
(contains eight electrons) and it has electrons of lower energy (Octet 
rule).
How to describe bonding?
1) The ionic bond: formed by the transfer of one or more electrons 
from one atom to another to create ions.
2) The covalent bond: results when atoms share electrons.
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Electronegativity(EN):
is the tendency of an atom to pull bonding electrons toward itself.
Dr. Ayman Amrat   10
Bond polarity: Polar  and non-polar Covalent Bonds
-The chlorine atom pulls the bonding electrons closer to it and becomes 
somewhat electron rich ⇒bears a partial negative charge (δ–).                    
-The hydrogen atom becomes somewhat electron deficient ⇒bears a 
partial positive charge (δ+).
When two atoms of different EN forms a covalent bond, the electrons 
are not shared equally between them.
Polar
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non-polar
: electron pair is shared. 
: electrons are transferred.
Dr. Ayman Amrat   12
Valence 
electrons
# Bonds 
# Lone Pair 
Electrons
C
N


            Quiz: