Post on 25-Jan-2016
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All matter has an electrical nature…
After dragging your feet across carpet, what happens when you reach out to touch something or someone?
Why does rubbing a balloon on your head make your hair stick to it?
Let’s find out….http://www.regentsprep.org/Regents/physics/
phys03/aeleclab/ballrub.htm
The electrical properties of matter can be summed up like this…
*Like Charges Repel Each Other
*Opposite Charges Attract
Every uncharged atom contains….Equal number of protons and electronsProtons have a positive chargeElectrons have a negative chargeMost atoms also have one or more neutrons.Neutrons have are neutral or no charge …see
where the name comes from?
The glue that holds matter together….The “sticky force” that holds matter together is called chemical bonding.
One kind of bonding is caused by positive/negative attraction
Another type of compound…Ions = electrically charged atoms or groups of atoms.
When an atom gains an electron it becomes a negative ion.
When an atom losses an electron it becomes a positive ion.
IN
OUT
Quick charge practice…I’ll give you the number of protons, electrons,
or neutrons you tell me the charge… ex: 7 protons = charge of +7
1. 10 electrons = 2. 6 protons =3. 5 neutrons =4. 2 electrons =5. 12 protons =
Doing the math…Sodium Ion
11 Protons ( Has a charge of +11)
+ 10 Electrons (Has a charge of -10)_____________________________________ (Has a total charge of _______ )
= Na +
More mathChloride Ion
17 Protons ( Has a charge of +17)
+ 18 Electrons (Has a charge of -18)_____________________________________ (Has a total charge of _______ )
= Cl -
IONIC COMPOUNDS =Substances composed of positive and negative
ions. It has no electrical charge
Ex : Na + + Cl - = NaCl
The charges have canceled each other out…just like in math!!
THIS IS THE MODEL OF NaCl ….CAN YOU TELL WHY IT IS AN IONIC COMPOUND?
DRAW ME IN YOUR NOTES!!!
HINT: THINK ABOUT “CHARGE”
Ions…..*Can be a single atom like a sodium cation or chloride anion.
*Can be a polyatomic ion(poly means many) = group of ions bonded together
ex// NO3-