Review Quiz More on Ions (Have your notebook ready) Octet Rule Today’s Agenda .w 10/7/10 Review Quiz More on Ions (Have your notebook ready) Octet Rule

Problem 1 Boron Atomic Number 5 Therefore I know this atom has 5 protons and because it’s neutral, 5 electrons 3e 2e 2nd 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 1st Orbital Shell 6n

Problem 2 Average Atomic Mass = Mass (%) + Mass (%) Iodine – 126 (34.7%) and Iodine – 127 (65.3%) Means: 126 (.347) + 127 (.653) 126.653

W Problem 3 Write the Chemical Symbol for Tungsten - 180 180 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 One negative Charge One positive Charge Potassium atom Potassium ion Electron 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

IONS...

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 balls can be added or taken away…

color = 2 green

color = 1 red

color = ?

3 red

color = ?

3 green

positive or negative charge the particles that make up atoms have either positive or negative charge +

positive and negative are opposites + + they cancel each other out + + +

+ net charge = zero + + + +

the positive (+) particle is called a proton +

the negative (-) particle is called an electron

in an atom, protons ( ) are in the center and electrons ( ) are on the outside + + + + + +

only electrons ( ) can be added or taken away + + + + +

this is an atom with 5 electrons and 5 protons + + + + +

the atom is neutral net charge = zero + + + + +

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

+ + + + +

+ + + + +

charge = ? + + + + +

charge = 1- (one minus) + + + + +

+ + + + +

+ + + + +

charge = ? + + + +

2+ (two plus) + + + + +

WHEN REMOVING ELECTRONS

WHEN REMOVING ELECTRONS THE RESULTING CHARGE IS POSITIVE

WHEN REMOVING ELECTRONS THE RESULTING CHARGE IS POSITIVE 1+ neutral

WHEN ADDING ELECTRONS

WHEN ADDING ELECTRONS THE RESULTING CHARGE IS NEGATIVE

WHEN ADDING ELECTRONS THE RESULTING CHARGE IS NEGATIVE 2 neutral

An atom with positive or negative charge is called an ION drum roll

Atoms with positive or negative charge SO... Atoms without charge are called ATOMS Atoms with positive or negative charge are called IONS

The number of protons in an AND... Notice that ONLY the number of e- changes (Only electrons are added or subtracted) The number of protons in an Atom NEVER changes (why?)

What do IONS have to do with anything??

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

ions make up acids and bases

ions keep your blood functioning

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 Rule A 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 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 6 Because of the extra electron More

Example continued What would the equation be? Fluorine Atom What Charge does it have? -1 Electron Fluorine Ion Fluorine Atom

Homework There is non today, but remember that your packet is due Friday. You also have a Quiz Friday and a test on Monday.