Student NOTE Packet.doc

NOTE PACKET

Unit 9

“Chemical Reactions & PTE”

NOTE

packet

I. Outcome 1 – Lewis Dot Structures (Electron Dot

Diagrams)

Lewis Dot Structures / Electron Dot Diagrams – Used to show the number of __________________ for an atom of an element.

>> __________ are used to represent each ____________________.

Example1: Na has ____ valence electrons

Electron dot diagram for Na

Na

Example 2: Sulfur (S) has ____ valence electrons

Electron dot diagram for S

S

Example 3: Neon (Ne) has ____ valence electrons

Electron dot diagram for Ne

Ne

Octet Rule

The Lewis dot diagrams and the chemical bonding of

Sodium (Na) and Chlorine (Cl)

II. Outcome 2 & 3 – Families of Elements & Oxidation

Numbers.

A) ___________ (vertical) on the PTE are called ___________ or _____________.

1) Families on the PTE are numbered: ___, ___, ______, ___, ___, ___, ___, ___, ___)

2) Elements in a family (same column) have ____________________.

B) ______ (horizontal) on the PTE are called _________. 1) On the PTE there are ______________.

++ Atoms are “_________”, “___________”,

__________” when they have ________________ and

are ______________.

++ So, an atom’s tendency is to create

____________________.

C) ________________ – Elements to the _____________ _________________ on the PTE.

1) Nonmetals are “_______________.” Meaning, they ________________ from other atoms to fill their

_________________.

2) Taking ____________ creates a _________ (__) ion. ____ = ________________.

Oxidation Number

Example 1: Chlorine (Cl) has _____ valence electrons.

It takes _______________ to fill its outer energy level. So, Cl has a _______________.

Written as an _________________: _______

D) _____________ - Elements to the ______________ _______________ on the PTE.

1) Metals are “_________________.” Meaning, they ____________ ALL _____________________ to other atoms to get to full energy levels.

2) Giving away electrons creates a ___________ (__) ____.

Example 1: Na has _____________________.

It easily gives _____________ away. So, Na has a charge of _____.

Written as oxidation number: _______

Example 2: Ca = ___ valence electron, gives away ____ electrons,

has a ___ charge, and an oxidation number of _______

E) ______________ – Elements that are in ___________ with the _____________ on the PTE.

+ Have properties of __________ & ____________.

F)

FAMILIES OF METALS, NONMETALS &

METALLOIDS:

METALS

(3 FAMILIES)

# of valence

Family

Name of Family

Family #

electrons

members

Alkali Metals

Alkaline Earth Metals

METALLOIDS

NONMETALS

(6 FAMILIES)

# of valence

Family

Name of Family

Family #

electrons

members

Boron Family

Carbon Family

Nitrogen Family

Oxygen Family Halogens

RARE EARTH ELEMENTS

Name

Where found Members

Lanthanide

Actinide

III.

Compounds

Subscipts: Numbers used to represent the

number of ________

A) How to:

1) Sodium (Na) is a _ (metal \ nonmetal) so it _ (takes in \ gives out) electrons to get to a full outer energy level. Sodium moves ___ (the number of) electrons so it is left with ___ (the number of) protons (+) and ___ (the number of) electrons (-). Therefore, sodium would have a charge of _____.

2) Sodium’s oxidation number = Na

3) Oxygen (O) is a _ (metal \ nonmetal) so it _ (takes in \ gives out) electrons to get to a full outer energy level. Oxygen grabs ___ (the number) electrons so it is left ___ (the number of) protons (+) and ___ (the number of) electrons (-). Therefore, oxygen would have a charge of _____.

4) Oxygen’s oxidation number = O

5) Draw electron dot diagrams for Na and O below:

Na

O

6) __________________________ -- represent compounds (which are the atomic combination of two or more elements) with the __ [metal \ nonmetal] having the __ [+ / -] charge written first, and the __ [metal \ nonmetal] having the __ [+ / -} written second. 7) What is an ion?

______________________________________________________________________________________

HOW TO WRITE CHEMICAL FORMULAS for IONIC COMPOUNDS

Reminder: OXIDATION NUMBER = The number that represents the ionic charge of an atom.

a) Find the oxidation number of each ion. (If the oxidation number is +1or –1, the number is not written. Ex: Cl-₎

Example: Fe+2 _Cl

-b) ___________________________________________________.

c) Criss-cross ________________________________________. .. the oxidations now become subscripts.

Example :

Fe

Cl

= Fe Cl

d) If the charges are the same or are divisible by 2 or 3 or any number, you reduce them.

In the chemical formula Fe Cl2 the subscripts are not the same and are not divisible by any number so we leave

the subscripts and write the formula: Fe Cl2.

PUT IT TO USE: If we were writing a formula for a compound of Mn+4 _{and O}-2_{, we would . . .}

Criss-cross the oxidation numbers

: Mn

O

Mn

O

Since the subscripts are divisible by 2, in this case, we reduce them and get:

MnO

Write formulas for the following:

8) Na Cl 9) Mg S 10) Fe (2) O

B)

1) Covalent Bonds – Chemical bonds in which the ____________________.

a) Formed between _________________________.

b) Atoms share ___________________________________.

c) Electrons are ____________________.

1. bonding pair = ________________ ….. “Owned”by ______________.

2. nonbonding pair …. “owned” by a ______________.

d) Always _______________________ at room temperature.

2) How to figure out Covalent Bonds:

a) ________________ …. Count the total valence electrons.

b) ___________________ …. Connect atoms using 2 electrons (bonding

pair) … arranged around a central atom, if there is one.

c) _______________ …. Work your way from the outside-in filling the octet

(“duet rule” for Hydrogen) rule.

d) _____________ … Are all valence electrons placed? Is octet filled for all

atoms?

3) Some Covalent Lewis Dot Structure Practice …

Formula: Hydrogen: H

Formula: Ammonia: NH

Formula: Ethane: C

H

IV.

Outcome 5 -- Balancing Equations

for Chemical Reactions

A) All reactions

(chemical, physical or nuclear) follow the ……

Law of __________________________________________

which states that the mass at the

_______________________________ must equal the mass

_________________ OR the number of _______________

on the REACTANT side must equal the number of

______________ on the PRODUCT side

.

B)

___________________________

represent elements.

(Ex:

_____ or ______

)

C)

Chemical Formulas

are short-hand ways of representing

____________________.

(Ex:

_____ or ______

)

D)

Chemical ________________

involve the interaction of two or more

forms of matter (elements and/or compounds) in which the

_______________________ (because _____________ are transferred or

shared).

E)

_____________________________

are short-hand ways of representing

a complete _________________.

(Ex:

_____________________

)

Some reminders

_________________

… the 2 in K

O is a subscript ….

_________________

…. the 3 in 3NaCl is a coefficient . . . .

STEPS TO BALANCING

EQUATIONS

Example Chemical Equation to be balanced: Na + O2 ---> Na2O

1) Determine the total number of atoms of EACH element on the Reactant Side and Product Side of the equation.

Na + O2 ---> Na2O

2) If the numbers of atoms of each element are NOT equal, place Coefficients where needed.

Na + O2 ---> Na2O

3) After adding Coefficients, Repeat steps 1 and 2 until you’ve BALANCED THE EQUATION.

TRY SOME:

Ca + S ---> CaS FeS2 + O2 ---> Fe2O3 + SO2

K + Cl2 ---> KCl Mg + O2 ---> MgO

Reactant Product