Download The Atom

The Atom
_______________________- Matter can be divided to its smallest part the atom.
Greek atomos- indivisible
_______________________- 1800’s an English Chemist
- All elements are composed of atoms
- Atoms of the same element are exactly alike
- atoms of Different Elements are different
- compounds are made by joining elements
______________________- atoms have positive and negative particles
_________________________- 1908 an English physicist
-atoms are mostly empty space
- have a small dense positively charged center,
the nucleus
- negative charge particles around the nucleus,
electron
_____________________- Bohr Model 1913, Danish Scientist
- electrons move in orbits around the nucleus
( just like a solar system)
- orbits or energy levels are located at certain
levels from the nucleus
_________________________- electrons do not move in a perfect orbit,
- only a prediction can be made where an electron will be
__________________________- A small positively charged nucleus
- nucleus surrounded by electrons ( an equal but opposite
charge of the proton)
1
The Atom
___________________- consists of two types of particles ( protons and neutrons)
- 99.9 % of the mass of the atom
- hundred thousand times smaller than the atom
______________________ - positively charged particles
______________________- mass of 1 amu ( atomic mass unit)
______________________- electrically neutral
- mass of slightly more than 1 amu
____________________- 1/2000 the mass of a proton
- negatively charged particle
- in an uncharged atom the electrons equals the protons
- circle the nucleus
_____________________- the number of protons in the nucleus
- always the same in an element
______________________- the number of protons and neutrons in an atom
- on the periodic table the atomic mass is the average of all
isotopes of an atom found in nature
How many protons and neutrons are in Carbon 12 and Carbon 14?
2
The Atom
_____________________- elements with the same # of protons but a different
amount of neutrons in the nucleus
Isotopes of Hydrogen
Protium Nucleus
Deuterium Nucleus
Tritium Nucleus
________________- the space in which an electron is most likely found in an atom
- energy levels
- location in a cloud that an electron is likely to be found
- electrons with a higher level are farther from the nucleus
- electrons with lower energy are closer to the nucleus
First level - 2 electrons
Second Level - 8 electrons
Third Level - 8 elecrons
Properties of element depend on the outer shell
- unfilled shells are unhappy and want to be filled
- 1st energy level can hold 2 electrons
- 2nd energy level can hold 8
__________- an atom is stable ( un-reactive)
if it has 8 electrons in its outer shell
3
The Atom
_________________________- the outermost shell is the valence shell
- the electrons in the valence shell are the valence electrons
Quantum Forces
_______________________- force that holds protons and neutrons together
________________________- holds the neutrons and protons in the nucleus
_______________________- positive and negative forces of electrons and protons
holding the nucleus atom together
Sub Atomic Particles ( Quantum Mechanics )
__________________- small particles that make up protons and neutrons
__________________- small particles that make up electrons
Fundamental Forces of Physics
4