Atomic Structure Atomic Structure ReviewReview
Mrs. FrommelMrs. Frommel
Physical SciencePhysical Science
Clover High SchoolClover High School
What makes up an atom???What makes up an atom???
Electron CloudElectron Cloud– Electron Shells (Period number)Electron Shells (Period number)– Electrons (negative charge)Electrons (negative charge)
NucleusNucleus– Protons (positive charge)Protons (positive charge)– Neutrons (no charge)Neutrons (no charge)
How do I know how many there How do I know how many there are?are?
The atomic number (above the The atomic number (above the symbol) tells you how many Protons symbol) tells you how many Protons and Electrons (in neutral atom) and Electrons (in neutral atom) A=P=EA=P=E
The atomic mass is the number of The atomic mass is the number of protons (also the atomic number) protons (also the atomic number) plus the number of neutrons M=A+Nplus the number of neutrons M=A+N
ExamplesExamples
Carbon Carbon
HydrogenHydrogen
What is an ion?What is an ion?
An ion is an atom that has lost or An ion is an atom that has lost or gained electrons gained electrons – Why?Why?
The outer shell is exposed and atoms want The outer shell is exposed and atoms want to have a full outer shellto have a full outer shell
– So?So? They lose or gain electronsThey lose or gain electrons
– 1, 2, or 3 valence (outside shell) electrons lose1, 2, or 3 valence (outside shell) electrons lose– 5, 6, and 7 valence (outside shell) electrons gain5, 6, and 7 valence (outside shell) electrons gain
What happens then?What happens then?
Gaining or losing electrons changes Gaining or losing electrons changes the overall charge of the atomthe overall charge of the atom– Losing electrons (-) gives the atom a Losing electrons (-) gives the atom a
POSITIVE chargePOSITIVE charge– Gaining electrons (-) gives the atom a Gaining electrons (-) gives the atom a
NEGATIVE chargeNEGATIVE charge– Examples: Ca FExamples: Ca F
How is an ion shown in How is an ion shown in writing?writing?
Ionic charges:Ionic charges: Positive (Mg)Positive (Mg)
Negative (Cl)Negative (Cl)
What is an isotope?What is an isotope?
An isotope is when an atom of an An isotope is when an atom of an element has more or less neutrons element has more or less neutrons than the stable version shown on the than the stable version shown on the periodic tableperiodic table
Why does this happen?Why does this happen?– These variations occur in nature and These variations occur in nature and
degrade (called half life) over timedegrade (called half life) over time
How are isotopes written?How are isotopes written?
Two ways:Two ways:
Carbon FourteenCarbon Fourteen
Phosphorus Thirty-SixPhosphorus Thirty-Six
This is confusing!!! This is confusing!!!
How can I keep it straight?How can I keep it straight?
The way you can always tell what the The way you can always tell what the element is: PROTONS (they don’t element is: PROTONS (they don’t change)change)
IonsIons are when the atom loses or gains are when the atom loses or gains electronselectrons
IsotopesIsotopes are when the atom has a are when the atom has a different number of neutrons (more or different number of neutrons (more or less) than the stable version on the P.T.less) than the stable version on the P.T.
What if I have more What if I have more questions?questions?
Email Mrs. Frommel:Email Mrs. Frommel: [email protected]@clover.k12.sc.us (or (or
through SchoolNotes or my website)through SchoolNotes or my website)
IM Mrs. Frommel IM Mrs. Frommel – on AIM screenname: BFrommelon AIM screenname: BFrommel
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