Today’s Agenda .w 10/7/10•Review Quiz

•More on Ions (Have your notebook ready)

•Octet Rule

Problem 1

5 Atomic Number

•Therefore I know this atom has 5 protons and because it’s neutral, 5 electrons

Boron

5p•There are 6 neutrons because the Atomic Mass 10.811 rounded up to 11 (which you look up on your periodic table) minus the atomic number 5 equals 6

6n

2e

3e

1st Orbital Shell

2nd

Problem 2Average Atomic Mass =

Mass (%) + Mass (%)

Iodine – 126 (34.7%) and Iodine – 127 (65.3%)

Means:

126 (.347) + 127 (.653)

126.653

Problem 3

Write the Chemical Symbol for Tungsten - 180

W180

74

This is the Symbol! I did not want the periodic box!

Ion Equations

A potassium atom changing to a potassium ion plus an electron

Electron

eKKPotassium atom Potassium ion

One positive Charge One negative Charge

So potassium lost an electron because it wanted a full orbital shell and you’ll see why…

Problem 4

Krypton has 48 neutrons

Atomic weight was 83.798 so you round up to 84. The atomic number is 36.

84 – 36 = 48 neutrons

red and green are opposites

assume red and green cancel each other

net color = neutral

take away one red

take away one red net color = 1 green

take away two red

take away two red net color = 2 green

net color = neutral

net color = 2 red

in this arrangement…

green is trapped inside.Only red ballscan be added ortaken away…

color = 2 green

color = 1 red

color = ?

3 red

color = ?

3 green

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the particlesthat make up atomshave eitherpositive or negative charge

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positive and negative are opposites

they cancel each other out

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net charge = zero

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the positive (+) particle is called a

proton

the negative (-) particle is called an

electron

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in an atom,protons ( ) are inthe centerand electrons ( )are on the outside

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only electrons ( )can be addedor taken away

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this is an atom with5 electrons and

5 protons

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the atom is neutral

net charge = zero

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5 (-) and 5 (+) = zero charge (neutral)

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charge = ?

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charge = 1- (one minus)

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charge = ?

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2+ (two plus)

WHEN REMOVING ELECTRONS

WHEN REMOVING ELECTRONS

THE RESULTING CHARGE IS POSITIVE

WHEN REMOVING ELECTRONS

THE RESULTING CHARGE IS POSITIVE

neutral 1+

WHEN ADDING ELECTRONS

THE RESULTING CHARGE IS NEGATIVE

WHEN ADDING ELECTRONS

THE RESULTING CHARGE IS NEGATIVE

neutral 2

WHEN ADDING ELECTRONS

An atom with positive or negative charge

is called andrum roll

ION

Atoms without charge are called ATOMS

Atoms with positive or negative charge

are called IONS

Notice that ONLY the number of e- changes

The number of protons in anAtom NEVER changes

(Only electrons are added or subtracted)

(why?)

ions make up the salt you put on your eggs in the morning

ions are required for your brain to function(ions allow you to see and understand this presentation)

ions are an essential ingredient in soap

ions are required for cellular respiration C 6 H 1 2 O 6 + O 2 C O 2 + H 2 O

ions make up acids and bases

ions keep your blood functioning

ETCETERA

C 6 H 1 2 O 6 + O 2 C O 2 + H 2 O

ions make up the salt you put on your eggs in

ions are required for your brain to function(ions allow you to see and understand this presentation)

ions are an essential ingredient in soap

ions are required for cellular respiration

ions make up acids and bases

ions keep your blood functioning

the morning

Octet RuleA concept of chemical bonding theory that is

based on the assumption that atoms tend to have either empty valence shells or full valence shells of eight electrons.

What this means is: Atoms want to have a full shell. So they will loss or gain electrons to obtain a full shell.

Beryllium (Be) Has one more electron in its atom so it wants to get rid of it to have a complete shell

Iodine (I) Has one less electron to complete its shell so it wants to gain one more electron

Example Fluorine

Fluorine (Chemical symbol F) has the electron configuration: (write it)

1s 2s 2p 2 2 5 But how many electrons can 2p hold? 6

Fluorine wants to have a filled outer shell. So most Fluorine atoms will obtain one extra electron and make it a Fluorine Ion

The electron configuration would be:

1s 2s 2p 2 2 6 Because of the extra electronMore

Example continued

• What would the equation be?

F eF

Fluorine Atom

ElectronFluorine Ion

What Charge does it have?

-1

Homework

There is non today, but remember that your packet is due Friday.

You also have a Quiz Friday and a test on Monday.