Post on 28-Dec-2015
ATOMS! WHAT’S IN
THEM?
PARTS OF THE ATOM
ATOMS CONTAIN A NUCLEUS AND AN ELECTRON CLOUD.
NucleusElectron Cloud
NUCLEUS… WHAT’S IN IT?
THE NUCLEUS HAS THE PROTONS
& NEUTRONS
ELECTRON CLOUD…
WHAT’S IN IT?THE ELECTRONS!
HOW DO YOU KNOW?
HOW DO YOU KNOW HOW MANY PROTONS ARE IN AN ATOM?
PROTONS= THE ATOMIC NUMBER (FROM THE PERIODIC TABLE)
ATOMIC NUMBER
ATOMIC WEIGHT
LET’S CHECK…
HOW MANY PROTONS DOES CHLORINE HAVE?
CHLORINE HAS 17 PROTONS
HOW MANY PROTONS DOES ARSENIC HAVE?
ARSENIC HAS 33 PROTONS
HOW DO YOU KNOW?HOW DO YOU KNOW HOW
MANY ELECTRONS ARE IN AN ATOM?
ELECTRONS= THE ATOMIC NUMBER (SAME AS PROTONS!)
LET’S CHECK…HOW MANY ELECTRONS DOES CHLORINE HAVE?
CHLORINE HAS 17 ELECTRONS
HOW MANY ELECTRONS DOES CHROMIUM HAVE?
CHROMIUM HAS 24 ELECTRONS
HOW DO YOU KNOW?HOW DO YOU KNOW HOW
MANY NEUTRONS ARE IN AN ATOM?
NEUTRONS = ATOMIC WEIGHT – ATOMIC NUMBER
SODIUM HAS 12 NEUTRONS(23-11)
ATOMIC WEIGHT
LET’S CHECK…HOW MANY NEUTRONS DOES COBALT HAVE?
COBALT HAS 59-27 = 32 NEUTRONSHOW MANY NEUTRONS DOES LITHIUM HAVE?LITHIUM HAS 7-3 = 4 NEUTRONS
LET’S REVIEW…HOW MANY PROTONS DOES MERCURY HAVE?
MERCURY HAS 80 PROTONS
MERCURY HAS 201-80 = 121 NEUTRONS
HOW MANY ELECTRONS DOES MERCURY HAVE?
MERCURY HAS 80 ELECTRONS
HOW MANY NEUTRONS DOES MERCURY HAVE?
What is the purpose of protons?
The number of protons tells you the identity of the element.
For example… you know that something has 24 protons in the nucleus, that means it is CHROMIUM!
Remember, the protons are located in the nucleus.
Protons…The number of protons also tells you the properties of the element.
For example… because calcium has 20 protons, it is a white, malleable, shiny, metal element.
Finally, protons are part of the atomic weight (mass).
Protons…
Determines Identity?
Determines Properties?
Determines Atomic Weight?
Determines Charge?
Protons Yes Yes Yes No
Electrons
Neutrons
What is the purpose of electrons?
The number of electrons tells you how the atom will bond with other elements.
Remember, they are located in the electron cloud.
Electrons…
When an element bonds with another, it exchanges electrons.
(for example H2 + O2-> H2O)
When this atom exchanges electrons, it becomes charged. Then, it is called an ion.
Electrons…
Determines Identity?
Determines Properties?
Determines Atomic Weight?
Determines Charge?
Protons Yes Yes Yes No
Electrons No No No Yes
Neutrons
determine the CHARGE of an atom. (when it is ionic!)
What is the purpose of neutrons?
The number of neutrons tells you the isotope of the element.
For example… Carbon-12 = diamondsCarbon-13 = medicineCarbon-14 = fossil dating
Neutrons…
Determines Identity?
Determines Properties?
Determines Atomic Weight?
Determines Charge?
Protons Yes Yes Yes No
Electrons No No No Yes
Neutrons No No Yes No
And, neutrons are the other part of the atomic weight.
Remember, the neutrons are located in the nucleus.