1. Matter & The Atom

2. Matter
The term matter describes all of the physical substances around us: your table, your body, a pencil, water, and so forth

3. Matter Anything that has mass and takes up space (has volume)
Includes all things that can be seen, tasted, smelled, or touched
Does not include heat, sound, or light

4. Matter is made of atoms

5. Models
Models are often used for things that are too small or too large to be observed or that are too difficult to be understood easily

6. Models
In the case of atoms, scientists use large models to explain something that is very small
Models of the atom were used to explain data or facts that were gathered experimentally.
So, these models are also theories

7. Early Models of the Atom Democritus
Universe was made of empty space and tiny bits of stuff
Called these tiny bits of stuff atomos
Atoms could not be divided

8. Early Models of the Atom Lavoisier
Demonstrated that burning wood caused no change in mass
Law of Conservation of Matter

9. Early Models of the Atom Dalton
All elements are composed of indivisible particles.
Atoms of the same element are the same
Atoms of different elements are different.
Compounds consisted of atoms of different elements combined together

10. Early Models of the Atom Thomson
Plum pudding model
Atom made of a positively charged material with the negatively charged electrons scattered through it.

11. Early Models of the Atom Rutherford
Mostly empty space
Small, positive nucleus
Contained protons
Negative electrons scattered around the outside

12. Early Models of the Atom Bohr
Electrons move in definite orbits around the nucleus

13. Early Models of the Atom Chadwick
Discovered the neutron

14. Modern Model of the Atom The electron cloud
Sometimes called the wave model
Spherical cloud of varying density
Varying density shows where an electron is more or less likely to be

15. Atoms Family Album
In the center of Matterville, there is a place called the Nucleus Arcade, where two members of the Atoms Family like to hang out. Perky Patty Proton, like her sisters, is quite large with a huge smile and eyes that sparkle (+). Patty is always happy and has a very positive personality. Nerdy Nelda Neutron is large like Patty, but she has a boring, flat mouth and eyes with zero expression (o). Her family is very apathetic and neutral about everything. Patty, Nelda, and their sisters spend all their time at the arcade.
+ +
Patty Proton
Nelda Neutron

16. Atoms Family Album
Around the Nucleus Arcade, you will find a series of roadways that are used by another member of the Atoms Family, Enraged Elliott Electron. Elliott races madly around the Arcade on his bright red chrome plated Harley-Davidson. He rides so fast that no one can be sure where he is at any time. Elliott is much smaller than Patty and Nelda and he is always angry because these bigger relatives will not let him in the Arcade. He has a frown on his face, eyes that are squinted with anger, and a very negative (-) attitude.
Elliot Electron

17. Atoms Family Album
The first energy street can only hold only two Electron brothers. The second energy street, called the Energy Freeway, can hold 8 brothers. The third energy street, called the Energy Superhighway, can hold 18 of the brothers.

19. Atomic Structure
Nucleus
Protons
Neutrons
Electrons

20. Atomic Structure Electrons Tiny, very light particles
Have a negative electrical charge (-)
Move around the outside of the nucleus

21. Atomic Structure Protons Much larger and heavier than electrons
Protons have a positive charge (+)
Located in the nucleus of the atom 

22. Atomic Structure Neutrons Large and heavy like protons
Neutrons have no electrical charge
Located in the nucleus of the atom 

23. Atomic Structure

24. Describing Atoms Atomic Number = number of protons
In a neutral atom, the # of protons = the # of electrons

25. Describing Atoms
Atomic Mass Number - equal to the number of protons plus neutrons.

26. Describing Atoms
Atomic Weight - average mass of the naturally occurring isotopes of an element .