electrons - Universal Companies

Report
Welcome back from spring break!
Week 12: Monday Do Now
1. Name one place that you would
like to travel to.
2. Why do you want to go there?
Corrections to PT Trends Quiz
In a different color pen make
corrections to your quiz.
If you finish early, help a classmate
Once you are done, place your quiz in
your Test Folder
Elements
• Elements are determined by their atomic
number
• Atomic number = Number of protons
• Atomic number does not change,
therefore the number of protons will not
change
Elements
• In a neutral atom…
Number of protons = Number of electrons
• However, in an ion, the number of
electrons will change
Ions
• An ion is an atom or molecule that has
gained or lost at least one electron
• If an atom gains an electron, it will have a
negative charge
• If an atom loses an electron, it will have a
positive charge
• Why?
Positive ions
• Ions with a positive charge are called
cations
• Atom will have more protons
+++++++++
Negative ions
• Ions with a negative charge are called
anions
• Atom will have more electrons
-- -- -- -- --
Examples of Ions
Lithium with a +1 charge = Li +1
Fluorine with a -1 charge = F
-1
Example A
Normally, Lithium has 3 electrons
3 negative electrons -3
3 positive protons +3
(-3) + (+3) = 0
Example A
Lithium with a +1 charge = Li +1
Li +1 has lost an electron
2 negative electrons -2
3 positive protons +3
(-2) + (+3) = +1
Example B
Normally, Fluorine has 9 electrons
9 negative electrons -9
9 positive protons +9
(-9) + (+9) = 0
Example B
Fluorine with a -1 charge = F -1
F -1 has gained an electron
10 negative electrons -10
9 positive protons +9
(-10) + (+9) = -1
*Independent Practice*
Write the number of protons and
electrons the element normally has and
then determine the
new number of protons and electrons
given the charge of the ion
Definition: the outermost electrons of an atom
Full Valence Electron Shell
What is a full shell?
• A full shell is 8 valence electrons
• Elements are more stable with 8
valence electrons
• Elements will gain or lose some
valence electrons in order to obtain 8
valence electrons
Elements want a full shell
• An element with less than 4
valence electrons will lose
electrons.
• This is why Alkali Metals (1 valence
electron) are the most reactive
metals. They are very close to a
“full” shell.
Elements want a full shell
• An element with more than 4
valence electrons will gain
electrons.
• This is why Halogens (7 valence
electrons ) are the most reactive
non-metals. They are very close to a
“full” shell.
“Full” Valence Electron Shell
Noble gases are
“inert” or un-reactive
because their outer shell
of valence electrons
is full with 8 electrons
Anion formation
Element
# Valence
Electrons
Gain or lose
electrons?
Ion that
will form
Chlorine
7
Gain 1
Cl - 1
Sulfur
Nitrogen
Anion formation
Element
# Valence
Electrons
Gain or lose
electrons?
Ion that
will form
Chlorine
7
Gain 1
Cl - 1
Sulfur
6
Gain 2
S-2
Nitrogen
Anion formation
Element
# Valence
Electrons
Gain or lose
electrons?
Ion that
will form
Chlorine
7
Gain 1
Cl - 1
Sulfur
6
Gain 2
S-2
Nitrogen
5
Gain 3
N-3
Cation formation
Element
# Valence
Electrons
Gain or lose
electrons?
Ion that
will form
Sodium
1
Lose 1
Na +1
Calcium
Boron
Cation formation
Element
# Valence
Electrons
Gain or lose
electrons?
Ion that
will form
Sodium
1
Lose 1
Na +1
Calcium
2
Lose 2
Ca +2
Boron
Cation formation
Element
# Valence
Electrons
Gain or lose
electrons?
Ion that
will form
Sodium
1
Lose 1
Na +1
Calcium
2
Lose 2
Ca +2
Boron
3
Lose 3
B +3
*Independent Practice*
Fill in chart
Circle all cations
Week 12: Monday Exit Ticket
Iodine has a negative 1 charge
1. Is Iodine an anion or a cation?
2. Write how many electrons and
protons Iodine -1 would have.
*Monday Homework*
Copy these elements down on a piece of
paper. Make a chart like the independent
practice and fill it out.
1. Lithium (Li)
2. Beryllium (Be)
3. Iodine (I)
4. Arsenic (As)
5. Krypton (Kr)
Week 12: Tuesday Do Now
1. What is an ion?
2. Classify the following as either
cations or anions
a.
b.
c.
d.
Bromine (Br)
Potassium (K)
Magnesium (Mg)
Sulfur (S)
Electrolytes
Electrolytes
• All ions carry an electric charge
• Electrolytes are substances that become
ions in solution and acquire the ability to
conduct electricity.
• They are present in the human body in a
specific balance that is necessary for the
function of our cells and organs
Electrolytes
NaCl(s) →
+
(Na ),
+
Na
+
(K ),
(aq)
+
2+
(Ca ),
−
Cl
(aq)
2+
(Mg ),
(Cl−), (HPO42−), (HCO3−)
Page R5 in appendix A
Read Electrolyte Balance in the
Body and answer the following 5
questions
If you finish early, check out the
Sodium-Potassium Pump on page
R6
Doctor Activity
• Using the information you have just read,
you will act as a doctor and answer
several questions about your patients’
electrolyte balances
• Leave your book open to page R5, you
will need to refer to Table 1B
You are the doctor
• A patient comes in with a Na+ level of 180
mmol/L. What should you be worried about?
• Hypernatremia
• Increased urine excretion (peeing too much).
• What happens if you lose too much water?
• Dehydration
You are the doctor
• A patient comes in with a K+ level of 2.0
What should you be worried about?
• Hypokalemia. Gastrointestinal conditions
• What do you think gastrointestinal issues
are?
• Gastro = stomach, Intestine = intestines.
• Stomach and intestine problems: stomach
upset
You are the doctor
• A patient comes in with a Na+ level of
120. What should you be worried about?
• Hyponatremia. Vomiting, diarrhea
• What do you think is a problem that
could come from vomiting and diarrhea?
• Dehydration from water loss
You are the doctor
• A patient comes in with a K+ level of 6.0.
What should you be worried about?
• Renal failure
• What organ are we talking about when
we say “renal failure”
• Kidneys
Kidneys
Normal kidney
Renal failure kidney
You are the doctor
• A patient comes in with a Cl- level of 90.
What should you be worried about?
• Hypochloremia: acute infection, burns.
• What does the word acute mean?
• Temporary
Take the sodium IQ quiz
on page R7
• Record your answers in your notes
Break
Challenge Question:
High pressure lamps (used along
highways and in parking lots) contain the
elements _____________ and
____________ in addition to sodium.
Lewis Dot Diagrams
X
 Draw the chemical symbol
 Treat each side as a box that can
hold up to two electrons
Count the valence electrons
Start filling the boxes - don’t
make pairs unless you need to
Lewis Dot Diagram
O
Oxygen has 6 electrons
in its valence shell
Start putting them in
the boxes.
Lewis Dot Diagram
O
This is the Lewis
symbol for oxygen.
Lewis Dot Diagram
Lewis diagrams of second period elements
Li
Be
B
C
Lewis Dot Diagram
Lewis diagrams of second period elements
Li
Be
B
C
*Independent Practice*
Draw Lewis Dot Diagrams for all
elements given
You should notice a pattern
Week 12: Tuesday Exit Ticket
1. Define the term electrolyte
2. Draw the Lewis Dot Diagram for
Sodium
3. What do the dots in #2
represent?
Week 12: Wednesday Do Now
1. Draw the Lewis Dot Diagram for
Fluorine (F)
2. Draw the Lewis Dot Diagram for
Potassium (K)
White Board Activity
Review of Lewis Dot Diagrams
Draw the Lewis Dot Diagram for…
Boron (B)
Draw the Lewis Dot Diagram for…
Nitrogen (N)
Draw the Lewis Dot Diagram for…
Chlorine (Cl)
Draw the Lewis Dot Diagram for…
Magnesium
Draw the Lewis Dot Diagram for…
Neon
Draw the Lewis Dot Diagram for…
Bromine
Draw the Lewis Dot Diagram for…
Bromine
-1
Draw the Lewis Dot Diagram for…
Lithium
+1
Draw the Lewis Dot Diagram for…
Arsenic
-3
Draw the Lewis Dot Diagram for…
The ion of
Sodium
Draw the Lewis Dot Diagram for…
The ion of
Iodine
Draw the Lewis Dot Diagram for…
The ion of
Phosphorous
Please return all white
boards & markers
Lewis Dot Structure & Bonding
Na
+
Cl
Which element is more electronegative?
Na + Cl
Na Cl
Cl is more electronegative.
Therefore, Cl will steal an electron
from Na.
Formation of NaCl
Na + Cl
+
Na
Cl
-
Na becomes Na+1 the cation
Cl becomes Cl-1 the anion
The + and - charges attract each other
and form a bond
F
+
Li
Which element is more electronegative?
F + Li
F Li
Which element is more electronegative?
F is more electronegative.
Therefore, F will steal an electron from Li
Formation of LiF
F + Li
F
-
+
Li
F becomes F-1 the anion
Li becomes Li+1 the cation
The + and - charges attract each other
and form a bond
Mg
+
O
Which element is more electronegative?
Mg + O
Mg
O
O is more electronegative.
Therefore, O will steal 2 electrons
from Mg
Mg + O
+2
Mg
O
Mg becomes Mg+2 the cation
Cl becomes O-2 the anion
The + and - charges attract each
other and form a bond
-2
Break
Challenge Question
Write out the electron
configuration for the
-1
bromine ion Br
Independent Practice
Questions?
Ask 3 other students before you ask
Ms. McCullough
Week 12: Wednesday Exit Ticket
Draw the Lewis Dot Diagram for
Sulfur (S) and Barium (Ba)
individually and then show how
an ionic bond will form.
Week 12: Thursday Do Now
Draw the Lewis Dot Diagram for
Sodium (Na) and Bromine (Br)
individually and then show how
an ionic bond will form.
Bonding
Key Points
1. There are 3 types of bonds
• Ionic
• Polar Covalent
• Non-polar Covalent
2. The difference between
ionic and covalent bonds
• Ionic bonds:
–One atom steals electrons from the
other atom
• Covalent bonds:
–Two atoms share electrons
3. The difference in electronegativity
between the two atoms will determine
the type of bond that forms
• Difference of 3.3 to 1.7 Ionic
• Difference of 1.7 to 0.3 Polar Covalent
• Difference of 0.3 to 0.0 Non-polar Covalent
Chemical Bonding Notes
• Read the 3 sections & complete notes
– Introduction to Chemical Bonding (Pg 165)
– Covalent Bonding and Molecular Compounds (Pg
168)
– Ionic Bonding and Ionic Compounds (Pg 180)
• Not all of the blanks are for bolded
vocabulary words. You will have to read
thoroughly.
What type of bond will form?
Practice Problem A
• What type of bond will form between Lithium
and Fluorine?
• Hint: you need to look up the electronegativity
value of both elements on page 153
Practice Problem A
• What type of bond will form between Lithium
and Fluorine?
•
•
•
•
•
What is the difference in electronegativity?
Lithium: 1.0
Fluorine: 4.0
4.0 – 1.0 = 3.0
Ionic Bond!
Practice Problem B
• What type of bond will form between Oxygen
and Hydrogen?
• Hint: you need to look up the electronegativity
value of both elements on page 153
Practice Problem B
• What type of bond will form between Oxygen
and Hydrogen?
•
•
•
•
•
What is the difference in electronegativity?
Oxygen: 3.5
Hydrogen: 2.1
3.5 – 2.1 = 1.4
Polar Covalent Bond!
Index Card Activity
• Every person will receive 3 index cards
labeled:
– I (Ionic)
– PC (Polar Covalent)
– NPC (Nonpolar Covalent)
• I will put up 2 elements on the board and
based on their electronegativities, you will
decide what type of bond will form
Sodium and Chlorine
3.0 – 0.9 = 2.1
Ionic Bond
Sulfur and Oxygen
3.5 – 2.5 = 1.0
Polar Covalent Bond
Calcium and Oxygen
3.5 – 1.0 = 2.5
Ionic Bond
Carbon and Hydrogen
2.5 – 2.1 = 0.4
Polar Covalent Bond
Hydrogen and Hydrogen
2.1 – 2.1 = 0
Non-polar Covalent Bond
Nitrogen and Oxygen
3.5 – 3.0 = 0.5
Polar Covalent Bond
Potassium and Bromine
2.8 – 0.8 = 2.0
Ionic Bond
Fluorine and Fluorine
4.0 – 4.0 = 0.0
Non-polar Covalent Bond
Potassium and Iodine
2.5 – 0.8 = 1.7
50% Ionic
50% Polar Covalent Bond
Week 12: Thursday Exit Ticket
1. What are the 3 types of bonds?
2. What type of bond would form
between Hydrogen and Sulfur?
3. What type of bond would form
between 2 atoms of Nitrogen?
Week 12: Friday Do Now
1. Ionic bonds _____ electrons
2. Covalent bonds _____ electrons
3. What type of bond would form
between an atom of Nitrogen and
Oxygen?
Covalent Bonds
Types of Covalent Bonding
Single bond- one pair of
electrons is shared between
two atoms
Chlorine-Chlorine
Cl-Cl
Types of Covalent Bonding
Double bond- two pairs of
electrons are shared between
two atoms
Oxygen-Oxygen
O-O
Types of Covalent Bonding
Triple bond- three pairs of
electrons are shared between
two atoms
Nitrogen-Nitrogen
N-N
Examples A, B, and C
Drawing Covalent Bonds in
Molecules
Steps to draw a covalent bond
1. Write out all atoms in the molecule
2. Draw Lewis Dot Diagrams for each atom in the
molecule
3. Count the total number of valence electrons to be
shared among the atoms
4. Arrange the atoms to form a skeleton structure for the
molecule
Each atom should now have an octet
Circle the electron pair bonds.
(Each atom wants a full shell of 8)
(Exception: hydrogen wants only 2)
5. Draw the electron pairs as lines. These are the covalent
bonds.
1. )
Drawing Covalent Bonds in Molecules
Silane: SiH4
Ammonia: NH3
Hydrogen sulfide: H2S
Carbon Dioxide: CO2
• https://www.youtube.com/watch?v=YHxHjnS
5y5E
Week 12: Friday Exit Ticket
Using Lewis Dot Diagrams…
1. Draw the bond between Lithium
and Sodium
2. Draw the bond between two
atoms of Bromine

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