ATOM

Smallest particle of an element with all its

properties

Periodic Table

H

ATOMIC NUMBER

SYMBOL

ATOMIC MASS

1

1.0079

Three main parts

•+PROTON

+NEUTRON

+ELECTRON

PARTICLE LOCATION CHARGE MASS

PROTON NUCLEUS POSITIVE

+

1 A.M.U

ELECTRON ELECTRON CLOUD

NEGATIVE

-1/1836 A.M.U

NEUTRON NUCLEUS NONE 1 A.M.U

Most of an atom is empty space. The nucleus of the atom contans amost all of the mass of the atom. A greatly enlarged atom might look like a marbel (the nuceus)insde an empty football stadium .

TO FIND # OF PROTONS

•ATOMIC NUMBER = NUMBER OF PROTONS

• NUMBER OF PROTONS = NUMBER OF ELECTRONS

NEUTRON• Atomic mass (rounded off)

-subtract

ATOMIC NUMBER

_____________________

NUMBER OF NEUTRONS

ISOTOPE• ATOMS OF THE SAME

ELEMENT WITH THE SAME NUMBER OF PROTONS/ELECTRONS BUT A DIFFERENT # OF NEUTRONS

CARBON ISOTOPE• HOW MANY

PROTONS, ELECTRONS AND NEUTRONS

• HOW MANY PROTONS, ELECTRONS NEUTRONS

COMPARE THE TWO CARBONS

1. HOW DOES THE MASS COMPARE

2. HOW DO THE PROTONS COMPARE

3. HOW DO THE NEUTRONS COMPARE

BORON• PROTONS=• ELECTRONS=• NEUTRONS=

ATOMIC NUMBER=ATOMIC MASS=

DEMOCRITUS

• 440 B.C

• DEVELOPED THE FIRST ATOMIC THEORY

DALTON THEORY• 1802

• ATOMS CANNOT BE BROKEN INTO SMALLER PIECES

• IN ANY ELEMENT, ATOMS ARE EXACTLY ALIKE

ATOMS OF TWO OR MORE ELEMENTS CAN COMBINE TO FORM COMPOUNDS

ATOMS OF EACH ELEMENT HAVE A UNIQUE MASS

MASSES OF THE ELEMENTS IN A COMPOUNDS ARE ALWAYS CONSTANT RATIO